Just thought I'd share a few of my favorite art websites:
Pigments Through the Ages is exactly what it says. You can click on a timeline and see how different colors were achieved at that time. There's also a section where you can deconstruct a painting, layer by layer!
Paint Like Pollock Move your mouse to start. Click to change colors. While away hours pretending to paint like a god!
Piece of Cake Fun and educational game where you can decorate cakes ala Wayne Thiebaud.