Dress codes at colleges? (specific question)

I know most sixth forms have casual business dress codes but what about independent colleges?

I've been interested in attending a college from day one, mainly because I dislike my school and wanted to go somewhere to get a feel of independence and where you are treated like adults. I know from some people that certain courses and colleges are more lax on what you can and can't wear to classes.

The real issue I have here is that I follow a few subcultures (fairy kei, which is a japanese fashion, for anyone interested) and pretty much my entire wardrobe is just pastels. I can tone it down a lot (to just a t-shirt, skirt, tights and flats) or it can be OTT (loooots of accessories and colours). I'd just like to find out what kind of dress codes A-level colleges have here in the UK so I know what to expect and whether I should stock up on more casual clothes.

Before anyone says "just ask them", please consider how embarrassing writing out an email to a potential school just to ask if i can wear a hoodie with bear ears on would be.

Is it generally just "whatever you want" or are there exceptions (like weird subculture clothing) to the "whatever you want" rule?

Thank you!