I agree that if it's not against the rules and as long as you like it than wear it.

I have a somewhat similar story- Justin (my husband) and I have been together since high school. During our senior year there was a rule that you could not wear all black, if you were caught wearing all black you'd be given a bright purple t-shirt to wear and they'd take your shirt from you. Well, Justin came to school wearing dark blue Jeans and a black t-shirt that had a bible verse on the front. A teacher sent him to the office for wearing all black and he was given a purple shirt to wear. I can't completly remember, I think he went home and changed out of the purple shirt at lunch.