BuddyPress display css on xprofile fields

I've been searching for hours now and I can't seem to local a very specific action involving Xprofiles. What I would like to achieve is having an xprofile field with a dropdown option that changes the css of the users profile depending on the options chosen in the dropdown.

So if a user selects Red in a dropdown menu, the body of the page gets a red background (not the page background - since I know there's a plugin for that already).

Any help would be much appreciated.