Ugh, I hate the "bodysnarking" thing with cosplay. In a world where it seems like more than half of all cosplayers who put effort into costumes at all are females cosplaying male characters, it's ridiculous to demand that anyone be totally accurate.
Probably the best Hiei (http://hakusho_yh.tripod.com/sitebuildercontent/sitebuilderpictures/hiei_iv.jpg)cosplayer I've scene was a black girl wearing (really cute) bright red glasses. She actually did the hair. And it looked insane.