I have a project where the site administrator would like to have a collection of different color schemes that she would like to be able to choose from to change up the look of her EE site.  In some ways this would be a css switcher-like feature but for an admin to do to affect the entire site for everyone as opposed to a feature that an end user can use.

Any suggestions for doing this in a way that is the most user friendly and least technical for the admin?

I just found a switcher demo page on the “A List Apart” site http://www.alistapart.com/stories/phpswitch/