Randomize stylesheet.css per page visit

I have a quick question what the best practice approach is with JS or Jquery concerning the randomization of stylesheets.

I plan to 5 to 6 different stylesheet.css documents handling only color elements (background, href, color). What I try to achieve is to randomize which stylesheet file (For example red, green, black, white) is loaded per user visit.

Is there a JS library for this purpose or a common practice in use already?