hmmm... from the other side: in my kids' school, there's a huge problem with the preppies vs. goths. This year they had to introduce a new school policy like that -- no dark nail polish, no tee shirts with certain designs on it, etc. (there's loads more but I forget what it is) It REALLY has cut down on the number of incidents of goths/preppy kids fighting. Sounds absurd that nailpolish would make such an impact, but it does. Last year my daughter came home nearly every day with a tale of some new fight, and this year we hardly ever hear anything about it. Unfortunately, even among your peers, how you dress affects how others see you.

Its only nail polish -- why get yourself into trouble with teachers and administration?