Do you care how sweaty you look?
If yes, wear black.
If no, what is wrong with you? Wear black.
ETA: That amused me, but for the sake of anyone who might be self-conscious, most dancers look great in every imaginable color. But when I dance for more than a few minutes, I sweat like crazy, and if I don't want to look like I've been dancing under my very own rain cloud, I've got to go with black or navy.