I like the clean, retro look for aesthetics. I also like being able to pick out teammates in a crowded field. One of our main sponsors is JBL, so we usually have orange as a highlight color but go with black or white as the main jersey colors. One year there were a handful of NorCal teams with black/white/orange and it was pretty annoying.
Every year I argue for orange jerseys and black shorts like Euskatel. Every year I get voted down. Of course, the year I finally prevail I bet 3 or 4 other NorCal teams go orange.