Gisk is right, there aren't any Kithkin in Ravnica… but who cares. 

So FVGT, he's, like, a half construct? Humans can't be colorless, unless they lack mana completely for some reason (which you've mentioned), which would be interesting.

And, if your character is a planeswalker, be sure to mention when they were awakened, how, and why are they sojourning in Ravnica.