Hemospectrum


 * Blood redirects here. For the aspect, see Aspect.

The Hemospectrum is the spectrum of blood colors possessed by trolls, which forms the basis of their caste system, with social and biological implications. The blood of a lusus has the same color of its associated troll, implying that it is a large factor in the selection of a lusus. Andrew Hussie has confirmed that there are only twelve possible troll blood colors, excluding mutations.

The cherubs possess different blood colors as well. However, their system is binary instead of a spectrum, with the color indicating a cherub's moral alignment – green for benevolent and red for malevolent.

Social Aspects
The caste system on Alternia is based on the color of an individual's blood. The hierarchy follows a rainbow, with red being the lowest and purple being the highest.

There are several terms covering chunks of the hemospectrum. Aradia refers to Tavros and herself (the two being the lowest on the hemospectrum) as "rust bloods," while Terezi, Vriska and Equius have all been referred to as "blue bloods."

"Lowbloods" is used to refer to the lower half of the spectrum, and "highbloods" is used to refer to the upper half of the spectrum. "Midbloods" is used, rarely, to refer to olive to cerulean bloods, but the castes within it are usually referred to as lowbloods or highbloods depending on their position in the spectrum.

Higher blood castes seem to have more lavish hives: both Equius' and Vriska's hives resemble castles as opposed to Aradia's humble hive. Both Eridan and Feferi wear jewelry as well.

Karkat masks his blood color in anonymity by associating to a dark grey color due to his candy red blood, a mutation that places him and his ancestor outside the hemospectrum.

Initially some of the trolls believed human blood works on a similar system, although only Equius, Eridan, and a sobered Gamzee seem to care much about the hemospectrum. Terezi is also very curious about human blood, specifically about how it tastes and smells.

It is possible that the blood-color caste system may correspond with medieval class systems on Earth.

Based on this supposition, purple blood would be high royalty, blue would be nobility of sorts, green would probably be lesser nobility, and red would be peasantry. The intermediary colors are harder to discern but may correspond to other roles in feudal society or may fall under the previously listed four groups.

On Beforus the hemospectrum was used to set up a system of social welfare in which the higher blooded trolls take care of the lower blooded trolls. The system is one of receding responsibility. The fuchsia bloods (the queen and her heiress) are responsible for the well-being of all her subjects, while burgundy bloods are free from any duties to take care of other trolls.

Each caste has an alphabet of 24 signs that are assigned to trolls, which are related to their aspect and their dream self's moon. This results in a total of 288 symbols for the alphabet. A troll is typically assigned a sign at birth, however the Sufferer and Kankri Vantas have no signs due to none being associated with their blood mutation. Notably, however, it is categorized under the limeblooded signs.

Hemotyping
Hemotyping is a tradition in troll society and potentially amongst cherubs where a person uses their blood color for writing and as the color of their symbol. While most of the trolls practice hemotyping, Karkat, due to his mutant blood color, refuses to partake in hemotyping, which causes Vriska to refer to Karkat's text as HS 4196. Calliope and Caliborn both renounced hemotyping HS 6862 (as one of the rules in their game); however, their symbols contain their respective blood colors as well as their gray text colors.

Half of the Hivebent trolls use a slightly different shade for their text as opposed to their exact blood color; despite this they use the shade of their blood color for their symbols as opposed to their text color. The Homestuck Kids also type in text colors corresponding to their eyes, but obviously this has nothing to do with blood.

Biological Aspects
Blood color seems to have several biological consequences in addition to the social consequences of the caste system. Troll tears are apparently the same color as their blood, though more diluted in color. Trolls lower on the hemospectrum are more likely to have psychic powers, but are more psychically susceptible as a result.

On the other hand, trolls higher on the hemospectrum seem to be physically stronger. Another obvious aspect is the different anatomy of land and sea-dwelling trolls. The latter sport fin-like protrusions and organs that allow them to live underwater.

Equius remarks that Gamzee has the highest blood possible for a landdweller and is as such more prone to violence and murder than the rest of them, and that he dreads to think what he would be without the pacifying influence of his moirail. This implies that trolls gradually become more violent the higher they are on the hemospectrum and is mostly in line with the twelve trolls followed in Hivebent. The only exception seems to be Feferi, who, despite being at the very top of the hemospectrum, displays no negative tendencies, although she might only be suppressing them by force of will, since she was screaming while attacking an imp HS 4478 (here). On a possibly related note, Aradia starts displaying more violent behaviour after entering her blue blood-fueled Soulbot.

In a dream bubble conversation, it was implied that high-blooded trolls are tougher than low-blooded trolls and likelier to survive grievous injuries. In the same conversation, Aranea states that the trolls' violent behavior is a result of 's conditioning of their race, implying that the high-blooded trolls may not be as unstable as was previously thought.

A troll's lifespan is tied to the hemospectrum with the having lifespans similar to humans, with the lowest two being slightly shorter than humans with the lowest caste living for HS 5968 (a dozen, or a couple dozen, sweeps) (roughly 30 to 50 years in human terms). Starting at the greens, lifespan and by the highest caste lifespans reach hundreds of thousands, potentially even millions, of sweeps. Mindfang, a cerulean blood, wrote in her journal that she expected to live for centuries and predicted the Summoner, who was destined to kill her, may very well not hatch for many sweeps, given the shorter lifespan granted by his lower position on the hemospectrum. Kankri stated that cerulean bloods with their centuries long lifespans could outlive hundreds of generations of burgundy, bronze, yellow and lime bloods, and dozens of generations of midbloods. The lower castes are significantly more common than the higher castes - described as having strength in numbers, despite having a much shorter natural lifespan and an increased likelihood of being killed.

Some castes have uneven sex ratios. Jadebloods are almost entirely female, the three blueblood castes (cerulean, indigo and purple) are mostly male, and fuchsia bloods have been consistently referred to as female (empress, heiress etc.). Also, higher castes seem to have sharper teeth and lower body temperatures.

Candy Red Blood
Candy Red Blood is an extremely rare mutation on Alternia. Karkat Vantas, his ancestor the Signless/Sufferer, and his dancestor Kankri Vantas, are the only trolls known to have this blood color. The Sufferer faced ostracism due to his mutation, and Karkat feared that the same would happen to him.

Due to its rarity, there was no lusus in the Sufferer's time that would choose him and the Dolorosa raised him herself; Karkat was only afforded a lusus due to the actions of the followers of the Sufferer, who prepared for the birth of another candy red blooded troll due to the prophecies told by the Sufferer. It has also been called "bright cherry blood" by Calliope and Terezi, the latter of whom associates its "smell" with cherries.

It is worth noting that Cancer's position in the Zodiac would place Karkat in the correct position in the Hemospectrum order of the post-Scratch trolls for a missing Lime Blood troll. Furthermore, his sign is regarded as a "Lime Sign" in the Extended Zodiac. This may suggest that Candy Red blooded trolls could be mutated Lime Bloods, mirroring the lime/candy red duality seen in Cherubs.

The abilities inherent to candy red blooded trolls are not shown. Unlike other lowbloods, Karkat is never seen exhibiting psychic powers. However, he is shown to have a great knowledge of the way the quadrants work (although this may be due to the large amount of romantic movies and novels he has watched and read), and both he and the Sufferer have managed to form bonds that exist outside of the four known quadrants. Both have also managed to unite trolls of different blood colors against a common threat.

This blood color is also known to exist in cherubs and is possessed by Caliborn/. This color sets them as the malevolent mind in their body.

Most other species in Homestuck have this blood color, chiefly humans, leprechauns, and carapacians.

Burgundy Blood
"Adventure motivates Rust Signs more than anything else. They crave new experiences, the wilder and farther-from-home, the better. They are confident and energetic, ready to face the unknown. This dynamism makes them great leaders, but it can also make them foolhardy. Often, they don't posses the level of caution they should for someone so willing to jump into new things. Their willingness to trust can get them into trouble, but they are also incredibly resilient. Their ability to bounce back from trauma and injury leaves them as the toughest sign class on the spectrum. Rust Signs make great friends and traveling companions, but they also can be selfish and quick to anger. If what they deem to be an acceptable level of "excitement" isn't happening around them, they have a tendency to try to stir some up. They love the drama. They have incredibly high expectations for themselves and for romantic partners. If someone doesn't live up to these, they may deem them not worth their time. If they aren't careful, Rust Signs can end up in a cycle of excitement, followed by crushed expectations, followed by a quick recovery and new flush of excitement."

- The Extended Zodiac

Burgundy Blood is the lowest blood caste in existence. Kankri referred to the color as "burgundy" in Openbound. "Rust" has been used on the album, but in the comic "rust" was used to simultaneously refer to the castes of Aradia and Tavros.

Aradia Megido, the Handmaid, Damara Megido, Xefros Tritoh and Xultan Matzos all have burgundy blood. Burgundy bloods are notable for having the shortest lifespans - having stated that they generally live only a dozen sweeps or two, or roughly 30-60 human years. They are the most likely to have psychic powers. This is a double-edged sword, however, as they are also the most psychically susceptible, and would be the first to die in the event of the Vast Glub. Despite this apparent vulnerability, Vriska is unable to use her powers to control AradiaHS 4145.

Aradia and her ancestor's psychic powers allow them to manipulate the position and velocity of objects. Using her tiara, the Condesce was able to emulate burgundy blood telekinesis, displaying Aradia's symbol and the same white auraHS 6773. Damara was able to HS 8461 (lift the Prospitian battleship) on LOMAX, through the concerted efforts of at least three of them at once, all the way from a dream bubble. Vriska HS 9420 (has suggested) that these telekinetic powers are common among the caste.

Aradia also possesses the ability to summon ghosts, commune with them and command them to do her bidding. After her death, she continued to linger on Alternia as a ghost, using her psychic abilities to interact with her surroundings. Hiveswap has revealed that all rustbloods possess the ability to communicate with the deceased.

Working together, the army of Aradiabots were able to HS 4492 (protect the other trolls) from the Black King's Vast Glubs.

Bronze Blood
"Bronze Signs have a warm and generous disposition, but you might not accuse them of it the first time you meet. They have a tendency toward being withdrawn and slow to open up with new people. This can make them come off as arrogant and cold, like they think they are too good for everyone, although the reality couldn't be further from the truth. In fact, they crave validation and companionship. They are very open-hearted, but if a Bronze Sign decides to dig their heels in, it can be like talking to a wall. More so than any of the other sign classes, Bronze Signs have a marked love of creature comforts. They crave stability and safety, and if they have the means, their homes will be full of beautiful things. Some might accuse them of being hedonistic; they would probably just claim to know what they like. As lovers they can be quite needy, wanting assurances that the affection they feel is reciprocated. Maybe because of this, they have a particular affinity for animals. Don't try to break a Bronze's Sign's routines-they'll resent you for it, even if oftentimes they are too polite to say so."

- The Extended Zodiac

Bronze / Umber Blood is the second-lowest class of blood. Trolls of this caste have also been called fudgebloods, and Terezi associates the blood's smell with chocolate. This was referred to as Bronze in both the music album and Gamzee's potion. Kankri refers to this blood caste as Umber; however, the term has never been used by post-scratch/Alternian trolls, and may be exclusive to Beforus.

Tavros Nitram, his ancestor the Summoner, and his dancestor Rufioh Nitram possess this blood color. Tavros and the Summoner have the psychic ability to commune with and command the various beasts of Alternia (and in Tavros's case the Underlings of the Incipisphere, possibly due to their Lusus prototypings). According to VriskaHS 9420, such abilities are typical of bronze bloods. It is not stated if Rufioh also shared in this affinity with animals, although both he and Tavros are avid players of Fiduspawn in which Tavros uses his abilities to commune with the game constructs.

Troll Kevin James has bronze bloodHS 4304, as do some or all cavalreapersHS 4016‎HS 5658‎.

In Hiveswap, Dammek is an example of a bronze blooded troll.

Yellow Blood
"Gold Signs are the reigning geniuses of the sign class spectrum, and chances are they know it. Witty and widely read, they enjoy conversation and debate, even when that conversation gets a little one-sided. They can come off as preachy, and they have a tendency to railroad, just driving into their interlocutors with the force of their intellect. Their arguments make perfect sense to themselves, but not always to those around them. Gold Signs are interested in a wide variety of topics, so they tend to be Jacks-of-all-trade, and can have trouble dedicating themselves to just a single hobby or career. They have a tendency to be high-energy, and can stress people out, including themselves. Their anxiety is such that they often need quite a bit of time alone with their projects. They can talk circles around most people, and they aren't afraid to use their intelligence to manipulate others to get what they want. They are good at making money, and also good at spending it. They aren't great financial planners, tending toward impulse purchases. In romance they lean toward partners who can keep up with them, both with their intellect and their energy, which can both be hard to match."

- The Extended Zodiac

Yellow / Ochre / Gold Blood is the third-lowest blood color. They are also very likely to have psychic powers. "Gold" is the color used in Gamzee and Jane's potion shop for a vial of Sollux's blood.

Sollux Captor, his ancestor the Ψiioniic/Helmsman, and his dancestor Mituna Captor are all powerful psionics, with Sollux and the Helmsman capable of using their mental powers to move massive objects at high speed; the Helmsman himself was used to power the Condesce's own battleship, making it the fastest out of all ships in her fleet.

Sollux is also capable of firing destructive blasts from his eyes, and the Condesce displayed the same ability while emulating yellow blood psionic powers. Vriska HS 9420 (has implied) that this specific set of powers is only common to mutants within the caste, which may explain the Captors' unconventional eyes. Sollux used his powers to make the bees from his beehouse mainframes sleepHS 3980 (which might be related to his ability to interfere with computer equipmentHS 4411), but he cannot read mindsHS 3927.

Sollux and Mituna are both gifted with "vision twofold", but this may merely be a trait unique to the paradox clones (possibly related to their shared Aspect). It should be noted that "vision twofold" is simply a reference to how Sollux still possessed his vision while having the ability to see the future (specifically, future deaths) unlike the traditional imagery of prophets being blind. In addition, both Sollux and the Ψiioniic/Helmsman die due to the Vast Glub released by Gl'bgolyb while they are directly serving their fuchsia blooded companions; in comparison, Mituna dies at the hands of Meenah's use of the Tumor.

In the era of the Signless, psychically gifted yellow bloods were commonly enslaved as HS 5958 (mages) or HS 5960 (helmsmen).

In Hiveswap Zebede is a yellowblood troll who is also a beekeeper, although he does not seem to have vision twofold.

Lime Blood
"Lime Signs are tumultuous, bringing great emotion and creativity to their endeavors. They are resolute in their decisions; if they are going to do something, they do it. They have a tendency toward melodrama, especially when they feel passionately about something, and their bad moods are loud and usually difficult to conceal. Hiding their feelings does not come naturally to them, so many Lime Signs cultivate a hard outer shell to hide the passionate, caring person inside. Lime Signs tend to have a large group of friends-they draw people to them with allure and the promise of excitement, and are usually unaware that they are doing it. They tend to focus on their own flaws, rather than their good points. Although they are exceedingly kind and empathetic individuals, many Lime Signs posses a mean streak. If you catch them on a bad day, they can be incredibly vicious. But it they take care to use their power for good, they make very loyal companions. Romance is extremely important to Lime Signs, and when they fall, they fall hard. They don't take rejection well, and a breakup can send them into a tailspin requiring an extended period of recovery."

- The Extended Zodiac

Lime Blood was once a very common blood caste on Alternia, but was hunted to extinction by the others due to its members' possession of powerful abilities that threatened the authority. Calliope has stated that the lime bloods had some unusual names. Kankri Vantas refers to members of the caste as "yellowgreens", considering the term "lime blood" offensive due to its historical connotations, implying that the caste was historically oppressed on Beforus.

The lime blood color was originally alluded to when the Grand Highblood was introduced, as there was a shade of green previously unaccounted for. The existence of the color was later confirmed by Hussie, and HS 5414 (the page) was retroactively changed to feature a lighter shade of green. This lighter shade fits in the color wheel between Sollux's yellow and Nepeta's green, where Karkat sits when the group is arranged by the procession of their zodiac symbols, possibly suggesting that he (and, by association, the Sufferer/Signless) would be a lime blood if not for the cherry red blood mutation. This was further changed slightly for the Hiveswap extended zodiac, along with Oliveblood, probably to make them more distinct from each other.

Calliope is a cherub with lime blood and proceeded to elaborate on the lime blood caste of trolls; however, at that point nothing more was said on the hemospectrum of cherubs. When asked if she had the powers that lime blooded trolls have, she answered Calliope being a lime blood may relate to how she uses Commonwealth spellings, as an old derogatory slang for the British is "limey". The color of lime blood amongst the cherubs is drastically different from that of the trolls, and looks similar to the web color harlequin. Slight variations of this color are used in Calliope's caduceus/asklepion symbol, in the colors associated with the depiction of Calmasis. Caliborn refers to her blood as "harlequin slime".

Olive Blood
"Olive Signs are, by and large, incredibly agreeable people. They are generous and enthusiastic, ready to offer help to anyone who needs it. Luck plays a large role in their lives; Olive Signs have a knack for being in the right place at the right time. And even in the case that their luck goes bad, they can ride rough patches out without falling too far into depression or hopelessness. That said, Olive Signs are most comfortable with things that they are familiar with; new places and ideas often alarm them, resulting in a dogmatic insistence that their way is the right way. They can be quite bossy and domineering, although that usually comes out of a genuine belief that they know best and can help the ones they care about. They are extremely faithful friends and lovers, ready to drop everything and go into helper mode. However, if their trust is breached, there's no going back. No one can hold a grudge like an Olive Sign, and they aren't afraid to just pick up and leave if they decide something isn't working for them. Romance and companionship are extremely important to them, so even if they get hurt, their hearts remain open."

- The Extended Zodiac

Olive Blood is considered the "middle class", and the color is referred to as HS 4062 by Equius. Equius and Nepeta simply call it "green", but this may not be the specific term, as there are two other shades of green on the hemospectrum. "Olive" has been used to describe a potion of the same color, which was HS 8300 (strongly implied) to be Nepeta's blood.

Nepeta Leijon, her ancestor the Disciple, and her dancestor Meulin Leijon are not known to have any sort of psychic power. This may indicate that somewhere in the green part of the hemospectrum, trolls start to be more likely to be born without psychic powers. This is also the blood color of Troll Will Smith's character on Thresh Prince of Bel-Air, and possibly Troll Will Smith himself. The threshecutioners included olive bloods within their ranks (as well as HS 3908 (bluebloods) of unspecified hue).

Jade Blood
"Jade Signs are the zodiac's caretakers. Intelligent and steady, they are excellent organizers and planners. They are detail-oriented, and can tend toward perfectionism, never satisfied with their endeavors. If you hire on a Jade Sign, be prepared for an excellent product, but also no peace until that project is flawless. They are fussy and particular, which can cause friction with those around them, although a Jade Sign holds no one to as high a standard as they hold themselves. Since they are shy with strangers and slow to open up, Jade Signs can often come off as timid or doormats, when really they just prefer to come at conflicts in a less combative way. Naturally loyal and loving, they make wonderful doctors, parents, and caretakers, whether they are taking care of people, pets, or plants. In relationships, they can be slow to open up, and need someone willing to be patient enough to go at their pace. If all of this makes Jade Signs sound soft and nurturing, they are, but keep in mind that they can also be fiercely destructive if those they care about are threatened. It takes a lot to make a Jade Sign snap, but if they do, take cover."

- The Extended Zodiac

Jade Blood is rare among trolls, and trolls with this blood color are given a unique role in troll society. In the past, jade blooded auxiliatrices were tasked to tend to the Mother Grubs in the brooding caverns. On Beforus, they were a predominantly female caste and their duties also included caring for wigglers.

Kanaya Maryam, her ancestor the Dolorosa, and her dancestor Porrim Maryam seem to be able to withstand the intense light given off the Alternian sun. Along with Daraya Jonjet, jadebloods seem to follow a goth thematic.

Kanaya, who is afforded the privilege of being brought up by a Virgin Mother Grub ("HS 4223 (an event so rare as to elude documented precedent)"), also eventually turns into a rainbow drinker (the Alternian equivalent of a vampire, who can withstand the planet's sun and radiates light) upon her death. Porrim became a rainbow drinker before her session began and the Dolorosa engaged rainbow drinker mode in one of the and (implied to) when meeting John. Kanaya and Porrim confirmed that being a rainbow drinker indeed directly relates to having jade blood. Kanaya also stated that their caste must have developed these abilities after working in the dark birthing caverns, while Rose suggested that the ability could have been developed to scare predators away from young wigglers.

Teal Blood
"Teal Signs are natural charmers. Social and flirtatious, they are great at parties and public speaking events. Even though they aren't afraid to use their many engaging qualities in both personal and business ventures, they have a strong moral sense. Right and wrong are very obvious to a Teal Sign, and it can frustrate them that others don't see the world the same way they do. Their idealism can make them strong defenders of justice, but it can also result in them being incredibly let down. Their strict adherence to procedure can lead to errors in judgement; they can be gullible and too quick to trust. They have vibrant imaginations, and enjoy fiction and roleplaying, and often those games will resemble the lives they want to be living. Deep down, they often long for a hero, someone they can idolize and count on, with the smarts and charisma to keep up with them. Unfortunately, they have a tendency to get involved with people who are very obviously wrong for them out of a desire not to be alone. Many Teal Signs are better off being single, at least until someone really extraordinary comes along."

- The Extended Zodiac

Teal / Aqua Blood is considered a high class in Alternian society. As a chromatic median between the green and blue castes, teal blooded trolls are not quite considered nobility, but still outrank the middle-class green blooded castes. Trolls of this blood color typically take civil servant positions, such as that of a legislacerator. According to Mindfang, typical lusii for this caste are cholerbears and spleenfowls, both implied to be big enough to carry their trolls.

Terezi Pyrope, her ancestor Neophyte Redglare, her dancestor Latula Pyrope and Tyzias Entykk all have teal blood. Redglare was a legislacerator, the Alternian equivalent of a lawyer who also doubles as a bounty hunter, and Terezi hoped to one day also have such a role in the Alternian legal system.

Both Terezi and Redglare also had dragons as their lusus, which Mindfang stated was quite unusual for someone, especially one of their blood color, to have. They also used their verbal prowess to affect others, rather than any sort of psychic ability. As Latula comes from Beforus rather than Alternia, it is not known what was expected of her as a teal blood.

Cerulean Blood
"Let's not mince words: Blue Signs are the ones to watch. Of all the sign classes, they have the potential to do the most good, but also cause the worse harm. They can be incredibly effective, and also incredibly destructive. Tell a Blue Sign this and chances are they would agree with you. They are magnetic and adaptive, able to adjust how they present themselves in any situation. They have a mask for every occasion. They are obsessively dedicated, willing to throw themselves into work, play, and everything in between. Because of this, Blue Signs are highly valuable allies and friends. However, they are very selective when it comes to who they let into their inner circle. You could be best friends with a Blue Sign and still never truly know them. They are powerful and successful, but they also tend toward jealousy. They often resent those they see as more well-positioned than they are. A well-adjusted Blue Sign is fantastically competent and inspiring, but a Blue Sign at their worst is a force for chaos. In love they can find themselves having to choose between their ambitions and their relationships, often with great difficulty."

- The Extended Zodiac

Cerulean / Cobalt Blood is the first rung of nobility. It is suggested that cerulean blooded trolls are unlikely to develop psychic powers. Usually this blood color is simply referred to as "blue," which can cause confusion as indigo blood is also referred to, and appears to be, blue. A potion based on her blood is referred to as cobalt, but Vriska herself called her blood "cerulean."

Vriska Serket, her ancestor Marquise Spinneret Mindfang, and her dancestor Aranea Serket all have cerulean blood. All three of them are very powerful psychics who are able to manipulate the minds of others to bend to their whim. All of them also have vision eightfold, allowing them to peer within the Magic Cue Ball to discover its secrets.

Aranea confirmed that psychic abilities related to mind reading and manipulation are an occasional phenomenon amongst cobalt blooded trolls. It is not known if this goes hand in hand with vision eightfold, or if this trait is simply unique to the paradox clones.

Mierfa Durgas is stated to be a member of this caste by her creator but appears to be listed as Indigo in Hiveswap judging by the prefix on her 2D image.

According to Porrim, this caste is male dominated, or at least it was on Beforus.

In Hiveswap, Mallek Adalov is a male ceruleanblood without vision eightfold.

Indigo Blood
"Indigo Signs are the enthusiasts of the sign classes. Friendly and cheerful, their optimism is contagious. Being around a well-adjusted Indigo Sign is always a good time. It's hard not to be drawn into their excitable orbit, just like they are drawn in by anything and everything that piques their interest. And those interests are liable to change at any time. Indigo Signs will often surprise their friends and family by declaring they are no longer interested in what just last week they were claiming was their jam. If you catch an Indigo Signs in a philosophical mood, they can be unexpectedly poignant and introspective. A downside of all this jovial enthusiasm is that Indigo Signs often don't know their own strength. They are known to be careless, both physically and emotionally, their conversations punctuated by jostling elbows and tactless comments. They don't usually mean to offend, and are often shocked to find out they upset anyone. When this happens, they can dig their heels in and insist they did nothing wrong. In romance, Indigo Signs need partners who can keep up with their expansive personalities, as well as forgive them for the occasional hurt feeling or two."

- The Extended Zodiac

Indigo Blood is the second-highest tier of blood amongst the land-dwelling trolls. They are considered part of the nobility, and as such they have a traditional rivalry/mutual kismesissitude with the sea-dwelling trolls. They are prone to violence as well because of their location on the hemospectrum. As with cerulean blood, this blood type is commonly called "blue," but the color has been alternately referred to as "indigo" when used as ink or in a potion.

Equius Zahhak, his ancestor E%ecutor Darkleer, and his dancestor Horuss Zahhak are all indigo blooded trolls. It is stated that Equius's enormous strength is unique to himself while his strength unawareness is a blueblood trait. It is unclear if the same goes for his ability to regenerate his teeth. Horuss is also stated to share Equius' great strength.

While Equius's strength would enable him to be an effective ruffiannihilator, he would prefer to be an archeradicator (an elite archer of the imperial forces and a role shared by E%ecutor Darkleer), in keeping with his Sagittarius theme. Also, Equius, Darkleer, and Horuss are all skilled in robotics.

Aradia became an indigo blood when her ghost inhabited the soulbot Equius constructed for her. As a result, she became much more violent (a trait absent from the lowblooded castes).

Indigobloods have a reputation of being snooty and stuck-up. It is likely that the entire caste cares immensely about the hemospectrum, like Equius.

The HS 4111 (archeradicators) are known to include indigo bloods.

According to Porrim, this caste is male dominated, or at least it was on Beforus.

Purple Blood
"Purple Signs are the workaholics of the sign classes. Ambitious and driven, they have a very specific path in mind to reach the pinnacle of their field, and will work tirelessly toward it. However, if their practical brains convince them that their goal is unrealistic, they may be slow to trust anyone with the secret of their true desires. They are often very funny, their wit veering toward the dryly macabre. Their fatalism can be incredibly humorous or terrible, depending who you ask. Purple Signs are usually the people who will say out loud what everyone else was thinking but was too nervous to mention. They are very stubborn, and once they've made up their mind about something, whether it be a restaurant choice or a political affiliation, it is difficult to change. They have trouble admitting they were mistaken, and also that they are upset. An oft-repeated phrase of the Purple Signs is, "It's fine, don't worry about it." They will let arguments fester rather than face them head on. In love they tend to be strictly monogamous and fiercely devoted, ready to pledge themselves to a person the same way they do their goals-utterly, and without reservation."

- The Extended Zodiac

Purple Blood is the highest ranked blood possible for land-dwelling trolls, and members of this caste are referred to as the "highbloods." Because of their position on the hemospectrum, purple blooded trolls are more prone to extreme violence and unpredictability, and it was for this reason that most were tasked as the violent subjugglators under Her Imperious Condescension.

Andrew Hussie stated that all the purple blooded trolls are adherents to an Alternian Juggalo-like cult that believes that "a band of rowdy and capricious minstrels will rise one day on a mythical paradise planet." Hussie also suggests that purple blooded trolls are granted psychic powers (the "chucklevoodoos"), which permits them to keep the lower blood castes in check.

Gamzee's psychic powers (possibly augmented by his Bard of Rage powers) allowed him to HS 5928 (facilitate the appearance) of a harlequin Jack Noir doll and Dream Cal in John and Dave's respective dream towers (dream rooms reflect the subconscious of players, so it's not clear if Gamzee was using a form of telepathy or conjuring the objects directly). Kurloz has demonstrated the ability to engage in two-way telepathic communication (possibly limited to eye contact), and what appears to be some sort of hypnotic gaze power.

Known purplebloods are Gamzee Makara, his ancestor The Grand Highblood, his dancestor Kurloz Makara, Barzum Soleil and Baizli Soleil. Barzum and Baizli are very semelhant, can telepathically communicate with eachother and share the same lusus and second name, although they are implied to be the same troll with split bodies due to a troll sillhouette yet to be revealed. The Grand Highblood served as a subjugglator, and it was Gamzee's ultimate goal in life to eventually take up this position himself.

All of the purple blooded trolls are also highly violent and unpredictable, but it is only after Gamzee runs out of the narcotic sopor slime that his true purple blooded nature arises. It is notable that Gamzee used an immense amount of psychic power, after becoming sober, to make the kids' session "terminal" (by creating a harlequin doll missing an arm and an eye in John's dream self's room, causing a chain reaction of events).

Kurloz also displays great psychic power, using it to command Meulin into serving himself, Gamzee, and presumably Caliborn. As it is a median color between the blues and the sea-dwelling purples, it is fitting that Gamzee lives on a shoreline and has an aquatic lusus. The only other lusus that is shown is a whale with purple blood, suggesting that all purple blooded trolls have aquatic lusii, but live on land. That would also mean it's common for purple bloods to live on the coast shore, to be close to their lusii as they would be out of reach otherwise.

According to Porrim, this caste is male dominated, or at least it was on Beforus.

Violet Blood
"Violet Signs are the universe's eccentrics. Forget marching to their own drummer-Violets built their own drum, and it's probably weird. A good deal of this is natural, but they also have a distinct bent toward contrariness. They are the sorts to give the popular thing a pass. Personable and outlandish, they are ready to make friends with anyone, although if they aren't careful their 'game for anything' attitude can come across as clingy or desperate. When their feelings are reciprocated, however, they are very loyal friends. Politics and humanitarian causes are often very important to Violet Signs, and they will turn their considerable inventive energy into a sort of noblesse oblige, happy to offer their nontraditional approaches to help others. At their very best Violet Signs are artistic and inspired, but they tread the fine line between genius and maniac. Too often their more esoteric interests can come across as perverse or untoward, and they can have a hard time holding their tempers, especially if they feel that they are being belittled or ignored. Intelligence is enormously attractive to Violet Signs, and often an intellectual connection is necessary for them to be attracted to a prospective partner."

- The Extended Zodiac

Violet Blood is the second-highest color of blood in the hemospectrum and is the first of two that exclusively belongs to sea-dwelling trolls, which are noted for their ability to breathe underwater, fin-like protrusions from their neck, and collapsing and expanding bladder based aquatic vascular system (which is merely a fancy term for the heart).

Violet-blooded trolls tend to be more violent than the others seeing as they are high on the hemospectrum, and express an extreme hatred towards the land-dwelling nobility. They also tend to be affiliated with piracy and are considered a part of the aristocracy. Karkat calls this blood type "purple" once; this was before coloUrs and mayhem: Universe A came out, and the blood colors were not consistently named.

Known purplebloods are Eridan Ampora, his ancestor Dualscar, his dancestor Cronus Ampora and Nektan Whelan. Eridan and Dualscar were violent towards the land dwellers, and they both sought a kismesissitude with their generation's main cerulean blooded counterparts and a matespritship with their fuchsia blooded counterparts. Cronus, the only known Beforan violet blood, does not display the same violence towards land dwellers as the others, as it was not the norm in the peaceful culture of Beforus.

Violetbloods are permitted to do just about anything on Alternia, and have very little restrictions in society, since they are considered royalty. They may publish anything in magazines that they want, whether it be harsh criticisms or what they had for lunch that day.

Fuchsia Blood
"Fuchsia Signs are the final of the sign classes, fittingly, also the most enigmatic. Possessing a strong imagination, they have an otherworldly quality to them that draws others in. Often, it has more to do with what they don't tell you than what they do, giving them an air of mystery that would more than likely perplex a Fuchsia sign if you told them about it. They aren't usually trying to be alluring-they're just lost in thought. Highly emotional, Fuchsia signs are sensitive and anxious, and tend to spend a lot of time worrying-about the world, the future, and what others think of them. They are artistic and talented, but can suffer from crippling bouts of depression, holding themselves to impossibly high standards. They have rich fantasy lives, and can get so caught up in daydreams that they sometimes forget to actually do things. Many Fuchsia Signs have trouble with follow-through, and it can take a lot to kick them out of their inertia. As far as romance goes, they need partners who are willing to put in the time to go at their pace, and who can handle how sensitive and emotional they can be."

- The Extended Zodiac

Fuchsia Blood is the highest and rarest color of blood in the hemospectrum. Like their violet blooded comrades, they are sea dwellers and are considered royalty. Fuchsia blood is so rare that those who possess it are destined to be the sovereign of all trollkind.

Feferi Peixes, the Condesce, and the latter's pre-scratch self Meenah Peixes are the fuchsia-blooded trolls shown in Homestuck. Only two trolls at any time have this blood color, an older one serving as the Empress of the trolls and a younger one known as the heiress to the Alternian throne; this is due to the Condesce killing her descendants once they've come of age. Prior to this, an Heiress may enforce an unknown but extensive amount of control over the home planet; the Heiress of the Hiveswap time period, Trizza Tethis, actively enforced a strict authoritarian rule, whereas Feferi favored a more hands-off approach.

Both the Empress and the Heiress are linked to the same lusus, Gl'bgolyb, known as "The Rift's Carbuncle", "Emissary to the Horrorterrors" and "Speaker of the Vast Glub", who HS 5963 (compels) the younger troll to challenge the older for control of the throne. Gl'bgolyb must be kept quiet by the fuchsia blooded troll, as Gl'bgolyb's voice is capable of killing trolls in ascending strengths and numbers depending on how loud it is, with the lower castes susceptible to anything above a whisper, to the devastating Vast Glub which kills all trolls in the universe save for the two fuchsia bloods.

Feferi and the Condesce are the only two fuchsia blooded trolls alive during the events of Homestuck, with the Condesce serving as Empress of Alternia off-planet leading the conquering forces, and Feferi staying on Alternia to tend to Gl'bgolyb. Because the Condesce is far away from Alternia, her psychic connection to Gl'bgolyb is severely weakened; as such, Gl'bgolyb's allegiance sways to Feferi.

As a member of the top blood caste, the Condesce is given a much longer lifespan. She also HS 5960 (has the ability to extend the lifespans of others), but it is unclear if this is related to her blood color or her pre-scratch self having been a Hero of Life.

Due to the events of Sgrub, neither the Condesce nor Feferi are capable of preventing Gl'bgolyb from releasing the Vast Glub, killing all trolls in the universe save for the Condesce, Feferi, the Handmaid (whose meteor lands in the future rather than the past), and the Sgrub players who manage to escape into the Incipisphere. Notably, Sollux and the Ψiioniic/Helmsman die due to the Vast Glub, but Sollux's multiple dream selves let him survive to play Sgrub.

Meenah, being the pre-scratch version of the Condesce, also has fuchsia blood, but she rejected the throne as it meant serving the entirety of Beforus rather than ruling over them with an iron fist.

It should also be noted that another lusus with HS 4361 (what appears to be fuchsia blood) is fed to Gl'bgolyb. Whether or not this is evidence of other possible trolls with fuchsia blood is unclear.

Trivia

 * Most of the blood colors are distributed at 30° angles on the HSV color system, varying by a few degrees here and there. The only exception is that lime blood is 73° instead of 90°, and olive blood is at 82° instead of 120°. This was probably done in order to make the different colors more visually distinct, and probably due to the fact that lime was added to the story later (without it olive would be assumed close to the 90° space with no blood color in the 120° space). Most of the colors are fully saturated (and the rest are close), but their brightness values have a wide distribution.
 * Indigo is also 230° instead of 240°, being a somewhat distinct difference. Equius' text color is still at the expected 240°, though, and is much darker in brightness.
 * The prefix "hemo-" means blood, and a spectrum is an array of colors; thus, a hemospectrum would be an array of blood colors, as it is in Homestuck.
 * The only notable Alternian native other than the trolls and their lusii is His Honorable Tyranny, whose blood is HS 5654 (pure black).
 * Nepeta's walls are covered in red blood, indicating that most of the Alternian fauna have red blood, and that the hemospectrum is unique to the trolls and their lusii.
 * It's possible that the variation of blood color itself is based on the blood pigments used by arthropods in nature (upon which trolls appear to be based). The predominantly land-dwelling insects use hemoglobin, which is a familiar red, while horseshoe crabs and many of the mostly sea-dwelling crustaceans use hemocyanin, which is dark blue when oxygenated.
 * The association between highbloods, royalty, and the sea probably comes from the nature of the last three signs of the zodiac (upon which the trolls are based) - Pisces (the fish) and Aquarius (the water bearer) are entirely aquatic concepts (just as Feferi and Eridan are entirely sea-dwelling), and Capricorn (the sea-goat) is a mixture of land and sea creatures (just as Gamzee lives by the sea, but not in it).
 * In the second walkaround of Act 6 Intermission 3, both wigglers have a skin color that is similar to burgundy and bronze blood. This could imply that wigglers have a skin shade that is slightly darker/lighter than their blood color, as Andrew Hussie had previously stated that there are only twelve possible troll blood colors, excluding mutations.
 * Various groups have been mentioned with uncertain positions on the hemospectrum:
 * It's not clear if the HS 4656 (blind prophets) were an organization, or if it's just a collective term for a series of historical figures with prescient psychic abilities.
 * The HS 5962 (laughsassins and ruffiannihilators) have also been mentioned as branches of the Alternian military. Their caste restrictions are unknown, however the laughsassins HS 5886 (appear to be affiliated with the subjugglators in some way), perhaps as either a branch of the subjugglators or an organization under their command, and Equius was HS 4111 (said to be qualified) for joining the ranks of the ruffiannihilators.
 * The HS 5927 (scienstiffs) are mentioned as a historical group which drew the ire of the subjugglators.
 * The fact that jade bloods (and thus Rainbow Drinkers) can withstand the sunlight is a reference to the fact that human vampires (which rainbow drinkers are the troll equivalent to) cannot stand the sunlight. On Earth, normal people are awake at day and asleep at night while vampires are awake at night and cannot touch sunlight - on Alternia with regular trolls and rainbow drinkers, this is reversed.