Ed Emberley, who thinks color habitually, here teaches color specifically: what it is, what it says, what it stands for. In a text that could hardly be more precise or apt, and illustrations that honestly exploit the mechanical medium ("This book is printed in red, yellow, blue and black on white paper"), he presents the three primaries, blends the three secondaries, lightens and darkens them--accompanied by asides on nomenclature (pink, not light red; gray, not light black) and the net results ("Are you surprised that brown is just dark orange?"). The color signals of a changing traffic light, of ambulance and police car, of port and starboard (on ships and planes) are ingeniously illustrated in the style of One Wide River. . . : then come the color-keyed states of mind ("I'm purple with rage," etc.) via tragi-comic cartoons complete to balloons. Concluding characteristically is a ghostly Halloween galaxy, a Victorian-type Christmas tree. Vivid instruction with a sense of humor--a top value in the wide spectrum of color books.