I work in a private high school where we have uniforms. I think they are cute! Our students have more options than most other schools around us, but everything has to be bought through a central store.
Basically, guys can wear khaki or navy blue pants. Girls can wear khaki, navy blue or a plaid skirt. We even added this cute little plaid sarong/skort thing this year. Everyone wears polos in different colors or button down oxford shirts in plain white or blue striped.
I can honestly tell you that I would much rather have gone to a school that had uniforms than mine that subjectively enforced the dress code. My senior year we were supposed to only wear shorts that were two inches above our knees.