My take on the situation:
Now people are right, in the real world the green hair and such wouldn't fly. However, At school, you should be able to wear what you want..
Actually, here's a story from the other day... My dad owns 3 restaurants., one of which I bust my ass at daily. This kid comes in with a backwards hat, west coast choppers t-shirt, and pants with one leg rolled up.
All I could do was laugh, and to be honest I wanted to yell at him for expecting a job from us. Had my dad been there that day, he probably wouldn't have even given him an app. But my manager let him fill one out anyways.
The point is, my parents taught me how to make good impressions, how to dress for interviews, etc, when I was 15 trying to get my first summer job. Making that kid wear a uniform at school won't change what he does on his free time. Parents need to teach their kids what is apppropriate for the work place, and how to get a job, etc.