My children wore the standard polo shirt/grey trousers/skirts primary uniform in the UK and no uniform ever since we moved to North America.
I used to be in the simple/practical/cheap and non ugly uniform is good camp, but it's actually been much easier as a parent since we dropped the uniform.
My children very quickly stopped being so interested in their clothes once they weren't forced to wear uniform 5 days a week. They tend to wear whatever is clean and works with the weather. dd is more fashion conscious I guess, she likes jeans or leggings, shorts in the summer (it gets very hot here) and t-shirts/overshirts.
Sure her outfits are fairly similar to many other girls, but in colours and styles she likes and suit her. She kicks back a bit about not being allowed to wear a beanie in class, and the time when she was told her top was too skimpy for PE when the boys were allowed to take their shirts off, but generally speaking we have no clothes related angst or rebellion here.
The idea of creating something for kids to rebel against is frankly bizarre. Would you do that at home with your own teenagers? Randomly invent some rule that you know they will kick back on, in the hope that they will then be compliant with something important? That makes absolutely zero sense to me. Arbitrary rules make children lose respect for you and be less likely to listen when you have important things to say. Teenagers aren't some sort of alien species who think in a different way to adults. If anything they are more concerned about justice and fairness, and more likely to get angry at stuff they consider to be some sort of authoritarian power trip. I sure know I felt like that in my teens!