I think I've got a great idea:
Stick to a white man who loves women, but simply declare that he is a transgender!
Born a man, looking like an average white man - but at some point he mentions that he considers himself to be a black woman. So there'd be a "female" protagonist.
Since that "female" character loves women, the character would also be homosexual.
That way, we'd get female, homosexual, black and transgender characters for the price of only one.