WordPress.org

This plugin adds an option panel to the front-page which enables your client or theme users to pick the colors and see the results live in the page. You have to define which elements and what CSS properties of them are changable.

Notes:

1.It only supports colors, and does not provide a UI to upload images or anything.

1. The front-end color picker appears for all logged-in users. I'm not sure how this should be handled, may be add an option to select which users can access it?