Originally Said By: Ray Borduin
Dynamic pages can be used, they just need to be browsed with http:// since they may not render properly if not browsed on the server. The restriction for html only is only for file:// references. Enter a http:// path to the .php page on your localhost, testing server, or live server and it can be used in the color picker. 
This worked perfectly for me too, however it might be a good idea to have some help text there about localhost for dynamic pages, and that you can enter a url to a web page, or image online instead of just browsing to a file with the file browser.
Other than that, I am running into no issues at all.
Looks great!
Tom
