This is by far the smoothest, most compact color picker I have found
Looking for a new color picker today, and I cam across this beauty! The 'Farbtastic' color picker... what a name! It requires jQuery, but is easily the best of it's kind I have ever found. It is extremely easy to implement and looks/works great (I really like the fact that it is mroe compact than most).
I just finished making a style customizer for one of our intranet applications that uses this to re-write our css and hence change the theme based on the user input. This tool was super easy to work with and cut my development time down by a huge margin. I can't say enough about this plugin! Hopefully I can get a post up about the online css customizer pretty soon.