You might as well accept it: whenever dress codes or sumptuary laws are enacted, a small subset of the affected group will try to skirt or disregard them. This is specially true with teens; after all, they are compelled to do a lot of things by the adults in power. Now many of these rules are well-intentioned and originated because of some looming problem, like gang activity or status signaling.
Take the reason why some schools prohibit athletic wear. Now guys like to wear team jerseys and other sports tokens anyway; however certain color combinations have been adopted as gang colors, and were prohibited. For some reason, the color often involves black. Well, there goes possible affinities to the Pittsburgh Steelers, the New Orleans Saints, the Seattle Seahawks, and the Oakland Raiders.
[Angel's Rule #47: Anyone who dresses like an Oakland Raiders fan is likely to be annoying. Doubly annoying if they go the full monty with makeup, chains, and spiked hair.]
But some schools, being proactive and sensitive to emerging nuances, scan for possible new signs or new things to worry about.
Like for example, suppose skaters or hoods or stoners in the local high school were to adopt beanies with propellers on the top. The clueless administrators would notice this, and notice moreover that their pet SGA members were not wearing them. So they would go, "Hmmm....Houston, we have a problem." or go into the full Oh Shit! mode.
And they would ban beanies, just in case.
Would about the ladies? Well, school big shots notice what they're wearing too. Too much pink is worrisome. So is wearing "Juicy" sportswear.*
But suppose one group of girls decided on a whim to dress like Sailor Moon and other Sailor Senshi.**
The teachers and administrators would go into full conniption, and ban the Senshiwear. And make a big deal out of it. Henceforth, any Sailor Senshi get suspended! And they would develop a post hoc rationale. Let's see...the skirts are short; they distract boys from studies or even (horrors!!) sports. The wearers are signaling that they use grass, or are sexually active.... The Senshi are a girl gang bent on utter domination of the school*** and a force bent on overthrowing the community....Or even worse, their short skirts might lead to dancing.****
Of course, the quickness by adults to adopt dress codes rules against fads practically guarantees that teens will have a possible way to shake things up. I remember looking at a beret I liked, and wondered if I could launch a fad. Sadly, I was not a school counterculture leader. At least I was not one of the student government lapdogs!
* Categorically, I refused to wear shorts with "Juicy" on the tush.
**A particularly innocent anime cartoon.
*** Cheerleaders are supposed to dominate the school. They wear short skirts too.
****The movie Footloose was based on Elmore, Oklahoma.
7 minutes ago