Seems perfectly fine to me. In my Artra setting humans are not quite so wild, but certainly commonly exhibit phenotypes that do not exist on Earth or at least are super rare here. And this is a setting where different humanoid species cannot cross-breed. On one in which they could there would be even more variation.
And about calling them humans, couple of points. The current humans on Erath are not only humans that have existed. Even within homo sapiens there were "ethnicities" that currently no longer exist. Prehistoric population with dark skin and blue eyes, etc. And human can be seen as wider concept than that, it can mean whole genus homo, not just sapiens. So neanderthals were humans. And of course in fantasy we could easily imagine other variations. I like how in Final Fantasy they tend to call human equivalents "hume" or "hyur" etc. I think this helps to communicate that whilst these people are human-like, they're not exactly out modern day Earth humans.