User blog comment:ZoshiX/Aura Magic Effectiveness/@comment-3103523-20160205161912/@comment-16075172-20160209163603

Not everyone has to have their own distinct aura; we can perhaps say that heavily related characters or something of the sort have the same aura color (i.e. troll hemotyping is an example because the blood/aura color would be the same as the ancestor)

I honestly doubt we'll ever come up with more than 16.7 million different characters, though we don't really need to come up with auras for unimportant characters, anyhow. Just any really "fitting" color should be enough for a character, and if it just so happens to coincide with another character's aura, then we can call it coincidence or whatever. (Note: HS f00 (ff0000) is a commonly used color at some points)

Alternate suggestion:

Auras can be presented out of the form in many different ways. It can be sort of like a number of auroras surrounding the being, it can look like a pulsating flame of energy, it can spurt out in geometric shapes, it can appear to spread out like a gas or liquid, it can have sorts of "glitch" effects around it, it can literally be the being in a ball of light, et cetera... while there is a limited number of aura colours to choose from, there are a greater number of possibilities in terms of how the aura appears to present itself from a being. So, "different auras" as a term can be greater than 16,777,276 (likely this number * number of different ways aura can be presented)

Alternate alternate suggestion:

Bi-aural (Maynef, Indra) and tri-aural (Gamelover?) also exist