I'm kind of confused. There are only three living trolls at the end of Homestuck. Assuming Vriska, Sollux and Aradia survived the Green Sun's implosion (which I doubt. I'm pretty sure it destroyed the dream bubbles), that ups it to six. So, logically, only those six blood colors should exist in the new universe's troll species, but the buildings in the canon fantroll panel show lime and cerulean decorations, plus Nektan and Mierfa themselves, who are indigo and violet. How is this possible?

We probably still have some corpses lying around the meteor.