It depends on the creature or individual. Non-sentient beings that use magic typically have a "colorless" aura, although a more likely explanation is that their aura's "color" is outside the visible spectrum.
Changelings always have a green aura, and unicorns typically have one that matches their cutie mark. Mine, for example, is magenta.
[brb blaming herself for not having noticed such an obvious tell before the wedding.]
[bbs]
Changelings always have a green aura, and unicorns typically have one that matches their cutie mark. Mine, for example, is magenta.
[brb blaming herself for not having noticed such an obvious tell before the wedding.]