Book excerpt: Asked by royalty to analyze why certain very expensive fabrics didn't meet expectations, a French chemist found that the dyes could not be blamed. M.E. Chevreul named the real culprit in a single paragraph-which he then expanded into a unified theory about every design discipline and, in 1839, the most ambitious and influential book ever written about color usage. Half a century later, On the Law of Simultaneous Contrast of Colors had become "the scientific foundation of Impressionist and Neo-Impressionist painting," according to Johannes Itten. "It is my Bible," said Winslow Homer. Vincent van Gogh called it "a luminous theory of colors," allowing "effects so violent that the human eye can scarcely stand to look at them." Chevreul explained how and why this occurred, but he then went on to discuss how it affects and can be exploited in any artistic context. Although this book is mostly noted for its impact on painting (and by extension, photography) it culminates with a chapter labeled Ten Principles for All Forms of Visual Art. He meant it, too: he prescribes design principles for tapestries, carpets, furniture, mosaics, churches, museums, apartments, formal gardens, theaters, maps, typography, framing, stained glass, and even military uniforms. Chevreul's basic ideas were clear but his explanations of how to implement them were convoluted even in the original French. The standard English edition, the only one available in print until now, has been condemned as plodding and misleading ever since it appeared in 1854. Today, this brilliant work reappears in a lucid form that goes far beyond a "translation." Color expert Dan Margulis has rewritten obscure parts, corrected errors, updated references, commented separately when needed, and added six chapters of his own. Technology stymied Chevreul's desire for extensive color graphics. Margulis has added them: photographs, line art, and reproductions of the works of those who swore by his ideas. And, he has used his digital expertise to explain what few critics have understood about how the painters were choosing their colors.