It's got good teaching in it, and I first learned about the two-primary system from that book. My biggest criticism is the title, which I assume is meant to shock us into involvement. It probably would not have sold as well if it were more accurately titled: Blue and Yellow Make Green (but not always). Perhaps we'll apply this wisdom to our coming Perspective Lesson titles: Straight Lines Do Not Exist! Stop Looking and Just Draw! Stop Drawing and Just Look! Everything You Perceive is Wrong! Your Eyes Do Not See Green, Yellow, Blue, or anything else — It's All in Your Brain! Maybe... But yes, informative book.