Other
Color Cube: Color Fun
Six activities sure to engage students of any age! Interactive games and puzzles let you play with color and create your own unique designs!
Other
Well styled.com: Webdesigner Tools: Color Scheme Generator
A totally cool concept! Choose your base color, your scheme (monochromatic, etc.) and the computer will show you what other colors go with it! There are even settings for various levels of color-blindness. A really cool art tool!!
University of Manchester
Children's University of Manchester: Talking Textiles: The Color Wheel
Interactive resource explains primary, secondary, tertiary, and complementary colors, the symbolic content of color, and the relationship between color and mood.