Goshen College
Some Ideas About Composition and Design
Starts with explaining visual elements, goes through design principles, balance, visual effects, and more. Teaching tips included too.
The Tech Interactive
Tech Museum of Innovation: Saturation
After defining saturation, this site provides an example and then begins an activity called "Experimenting with Saturation," involving degrees of saturation and saturation with images.
University of Saskatchewan (Canada)
University of Saskatchewan: Value & Color
Basic color theory is discussed in relaton to computer art applications. Illustrated.