Looking for a good reference book on color? Color Harmony Compendium, a collaboration between Terry Marks, MINE, Origin and Tina Sutton is what I'm perusing at the moment. I love color theory and although a drudgery to some I think any person dabbling in the visual arts should take at least one course in their lifetime. I took mine at the New England School of Art and Design - back in my early 20's. Sometimes it's nice to have a visual reference guide when you'd like to evoke a certain mood or you're just looking for a new color palate to experiment with. I just took this out of the library but I think I'm going to purchase it to add to my library.