Digital color theory
A quick color course and how it will be implemented as a device independent feature in CSS4.
Correspondance between pitch constellation and color wheel.
Color picking fun
Colors for data scientists. Generate and refine palettes of optimally distinct colors.
How to make colourful liquid reactions
Color search Flickr
plugin adds CMYK to Gimp
Here's a recipe to make your own watercolor paints. These vivid, non-toxic paints can be used wet or allowed to dry and used like regular watercolor paints.
Share and find color palettes.