I simply don't know what the fuss is. You go to school; you wear the uniform as directed. There is no need to ask "what's wrong with a brightly coloured hijab". It's against the rules - that's all you need to know. Uniforms are designed to be, well...uniform. There's a good reason for it and the excuses made on here for non-conformity simply don't wash.
My old school was founded 408 years ago. During that time a rigorous uniform policy has been enforced. In the seven years I was there, there were pockets of uniform rebellion from time to time. I took part in a minor one of them myself - a tale I related here a week or two back. It was swiftly quashed by the school assisted by my parents when they got to hear about it.
The tragedy with this episode is that the rebellion is being defended and the rebels are being given air time. As one of them said, when something else upsets them they will rebel again. The lunatics, I'm afraid are slowly taking over the asylum.