Tanya is the only female fighting game character that I know of that appears to be unambiguously black.Never thought that there was any dispute that Christie is black. Brazil pretty much is like the Dominican Republic in regards to how they consider one black. Some of those with clear African lineage would deny it while others with even less defining features still would consider themselves black. There is no dispute with who's considered white though.
I would also figure how Tekken has mostly kept the character the same race as the people who had invented the martial art that's associated with the character. I don't think I've seen a single video game where the developer drew a distinctively looking black woman. Elena, Vanessa, Lisa, Tanya, and Jade I've all seen been disputed, but Elena less so probably only because she's actually from Africa.
It almost never seems to be questioned when the male is black. Only Dudley is the only who has been, so it sounds like to me if you have natural hair your blackness is never in question. If your hair is straightened people are quick to take away the African association.
EDIT: Forgot about Storm from Marvel