In school I was never able to dye my hair blue or red, only "natural" colors.
What is so wrong with unnatural dyes? Whenever the school admins saw someone break the dress code, they justified it with "it's a distraction".
It is not my job to keep people on task. Dyed hair doesn't disrupt class, it's not illegal, and it's my hair so I can do whatever I want with it.
The same thing can be applied to actual dress. Obviously I wouldn't wear a shirt that exposes everything on my chest, but what's wrong with leggings? Unless whenever you bend down, the leggings thin and show your underwear, they're fine. Denim leggings, or "jeggings" are still leggings, so why can't I wear the fabric ones? Again, it's not my job to keep guys from looking at, like, my shoulder. Yoga pants never hurt anyone.
I understand that my school is trying to prepare us for the professional world, but not everyone is going into a white-collar job. I'm going to work at a zoo or a sanctuary, so I just need to wear something that's light, comfortable and covering. Some people plan to work from home, like my boyfriend, and of course you're not going to wear a polo and khakis on the battlefield.