Is it possible to get the user to select a CSS template themselves for their profilepage? Just a field with a dropdownmenu so they can select a css template. It sounds so simple, so why hasen't it been done yet?
(Excuse me for my unknowingness, for I don't know anything about good coding, I'm a designer.)
I am 99% sure that you can write a plugin that loads css at the top of the profile. If someone wants to write it, I can give support for the effort in this thread.