I don't see why you would see this as racist or weird or whatever. Different people have different tastes and if your desire is to submit to a black woman, then that's your desire. Now if a woman comes up to you wanting to dominate you and she's white and you refuse simply on the fact of her race, then you may have a problem. I'm white and the first woman who ever dominated me was black and race was something that we very rarely discussed as it's a factor that's just not really all that important. So I think your desires are perfectly normal and you don't need to feel bad about them.