Nifty colour picker.

"Sim Daltonism is a color blindness simulator for Mac OS X. It filters in real-time the area around the mouse pointer and displays the result — as seen by a color blind person — in a floating palette."

Franz Ferdinand colour palette at ColourLovers, with each colour named for a member of the group. Good Lord, they really are famous, eh?

The Colour Wizard lets you type in the value of your colour and get an automatic return of that colour's complementary colour, split complementary colours, analogous colours, chromatic variations, shade and tint variantion and saturation variation.

php script to generate a color palette based on an image.

a directory of nice colors