This is still a work in progress and I need to take out the project specific things I have in there that are related to our app, but its working well and is based on CCControl http://www.cocos2d-iphone.org/forum/topic/19915 (by YannickL) to dispatch events through Cocos2D, we are going to put the project onto github but in the mean time here is the project as a zip, http://www.creativewax.co.uk/private/SketchShareColourPicker.zip

you can see the colour picker in action on a preview video of our Sketchshare app here (at 0:53)
| Get the Video Plugin |
currently optimised for iPad
This isn't built the best way at the moment, but after people beta testing the app and people seeing the video there was a lot of requests for people to see how we did the colour picker, so being nice we thought we would just put it up for all to enjoy :D
feedback and improvements most welcome ;)
twitter - @creativewax