The Yale University Press recently reprinted an expanded version of Josef Albers' classic book Interaction of Color. Unlike many books about color, this one eschews most discussion of optics and wavelengths and the physics of light. It's not about theory and systems. Instead, this one is meant to be a very hands-on book---experiment and observation. Each small chapter is dedicated to a particular color concept, a sort of visual consciousness-raising, if you will. Though it only takes an hour or two to read the book and ponder the examples, actually following through with the projects takes hours and hours of cutting out paper samples and ceaselessly arranging and rearranging.
To offer one tiny quibble, the layout of the text really threw me for a loop. The sentences are arranged in such a way that they don't continue to the true margin on the side of the page, neither making a justified block of text or a comfortable right-ragged edge. I'm not sure of the reasoning for this decision. But it really made the whole thing harder to read.
That aside, it's a fantastic book.