This looks pretty solid so far... Quick cursory overlook I wonder if you couldn't integrate the new API stuff I added in the jQuery Color Beta 2:
https://github.com/jquery/jquery-color and avoid needing to include this code inside your colorpicker. Color2 will be baked into ui in 1.9 most likely, probably sneaking its way in inside of effects.core.
If there is ever any hope of this landing in the project, you should really take a look at the style guide. White spacing, etc. is out of control in this code file :)
Also, you might want to think about wiring up a demo on the gh-pages of your repo