I don't think my school has any problems or rules with hair.
I know you're not allowed to have coloured strips in your hair, but that's about it. And even then, that's just colours like light blues, pinks and greens. The ones that really stand out.
Hair length isn't a problem. For the whole of last year, I had been growing long hair. It came down to about my shoulders. I have recently had it cut though, and it doesn't pass my ears. I'm not too sure if I prefer it though, but it's defintely more managable.
One of my friends, a boy, has really long hair though, and he doesn't have any problems with it via teachers or rules. The worst he gets is us taking the piss out of him, but, his hair does go right down his back, and he looks similar to a Wookie.
My school tends to focus more on Uniform really, or atleast has been for this year, due to a new Headmistress.
Obviously, being an English school, we have a school uniform, which includes;
School Polo-Shirt
School SweatShirt
Black school trousers
Black Shoes - Formal
Black Skirt of decent length - It can't be higher up than your Hands Width from your knee. - For girls.
The only changes this year really, are on how leniant they are towards peoples following the dress code.
So, they're much more strict on girls makeup;
Minimal amounts of eye-liner and blush. No Nail colourings or fake nails.
No Hoodies at all.
Coats/Jackets are only to be worn outside.
Absolutely no trainers.
You're allowed to wear a white T-Shirt underneath your School Polo-Shirt, so long as it does not come out of the shirt, as in it's arms being longer than the School Shirt'.
The T-shirt is also not allowed to have any markings/logo's that can be seen through the School shirt.
I believe only a few people have been sent away/suspended from school due to not following the dress code. One of them was a girl who refused to remove her makeup. Another one was a boy who refused to give his Hoody in. And another one, was a boy who had over the summer holiday's, had a Tattoo applied on his side.
I've no idea what they said to him about it, since you can't really remove a Tattoo overnight, nor cheaply.