You're almost there! She hasn't gotten over the idea that having sex outside your relationship is possible. Forget about the black thing for a moment and set your goals on making friends with swingers. They are open-minded to the idea of sharing. Talk her into going to a swingers club and watching people share. You don't have to partner swap there, just be around people that do. Make friends with other couples so your girl will talk to the other girls and feel more normal about it. Make it a point that you are going there just to have, enjoy the atmosphere, and satisfy your curiosities. Make it feel like it is her idea if you can. After a while, she will feel more comfortable and you drop the hint that you could always start off slow with just her having fun. Of course, If she bites, it sounds like she already would be OK if the guy is black.