If you get on a little later, sometimes there aren't as many immature racist bitches out there, and its all clean play.
You can, as someone else mentioned, just find a "cool" room, I play(ed) :( with LuFeng's clan all the time anf they are really cool, there are a fair bit of black men on the clan, but they are really cool and I've never heard any racism happening in the room, from either side.
I remember we were in a clan war (actually Lu, we were warring a friend of yours's clan, umm Eat_These, Be_moreChic are the ones I can remember) and they also had a fair bit of black people on their team. I needed to get in, but they had an extra guy in, and our guy told him to get out, he wouldn't listen, so he ended up getting really really mad. By the time I got in, I heard him drop the N bomb, and our own clan got pissed off at ihm aswell, particularly the leader....I wasn't very pleased with him....In the game after that, he was being a baby and said they started it too...
Mostly people be racist when they have their backs covered....like my clanmate. That was one of the reasons we didn't get along, I'm very glad I don't play with him anymore.