Board Thread:Speculation House/@comment-165.138.37.20-20171122222909/@comment-4010415-20180104032540

ElectricKitty24 wrote: We've seen her eyes turn both blue and red, so we know she's capable of that (even if it makes no biological sense, but whatever). Apparently, in real life, brown eyes are blue underneath that brown color. There's apparently even a laser treatment that can make your body remove the melanin that makes your eyes brown, thus permanently giving you blue eyes.

So... really, Ilia's chameleon trait could be allowing her to change the proteins in her skin, hair, and eyes to make them appear different colors.