Paint it as you see it. If it looks like something else to others, well, that's art.

Hey, I have an artist friend (who's really talented) that has a difficult time distinguishing brown and greens. Sometimes, he would ask us which is which.

Another schoolmate is also colorblind but creates amazing portraits though I noticed that it's always black and white.

These two would come into mind first if someone's gonna ask me if I could recommend somebody for art.

There's also an artist online who takes videos of her creating art with a different colored light on. Not the usual white/warm/cool lighting but like led lights (red, etc.). It's interesting because you can't see the real colors so nobody knows what the result would be like but still ends up incredible even with the playful colors.