I like that you decided to use some base64-packed images instead of using anything external; good idea.
You may want to include something about what browsers are supported. As it is, the page is completely broken and not usable with IE9 (1).
Nice work, though!
 - http://i.imgur.com/d7JFq.png
Still not quite perfect, but not totally broken.
Seriously though, how would you go about picking the same colour twice without just giving a finite list of colours and unique names for each ?
Exactly! I don't know why this isn't provided more often, at least as an option.
Too bad it isn't possible to draw color wheels in pure CSS, AFAIK...
A color wheel needs the color to vary with the angle, not with the radius.
From what I know, CSS3 doesn't do that.