Allow people to make there own theme, with option for a programmed color generator with Hexadecimal text as color, or allow people to make the're complete own CSS project for this website, and allow them to use it, i think it would be awesome for those who can do CSS

There were themes made by users a while back, and there was actually a Guide on it by Gary, a senior moderator. Unfortunately, I'm not sure where it is. You can probably ask a moderator about submittal requests.. I'll look for it myself as well.

hmmm... thats too bad they removed it

You can create user side css to override a site in most modern browsers.