Defining color is a simple matter-visible light of a particular wavelength. Or is it? It turns out that the pigments and dyes responsible for hues have many remarkable characteristics, most of which we rarely ponder. Journalist Finlay's first book is a blend of travelogue and historical exploration about the myriad ways color takes on meaning for us, whether as a matter of aesthetics, economics, war or culture. The book has no overarching theme-it's all byways, an approach that works. Insofar as there is a thesis, it is that visual expression falls just behind procreation and the search for food and shelter as a fundamental human activity; countless peoples, Finlay reports, rank color and art among their primary concerns. During her journey, both literal and literary, Finlay learns of many little-known tribes and historical curiosities: too-trusting Puritans purchasing cheaply dyed black clothes destined to turn orange in a matter of weeks; the rise and heartbreaking fall of the art of the Pintupi tribe in barren central Australia during the 1970s; and the once-supreme economic clout of indigo from Bengal-to take just three examples among dozens. To delve into this book is to see the experimental, scientific side of the old masters and the artistic qualities of inventors and explorers. This is not a scientific work-those interested in rods and cones should look elsewhere. Thanks to Finlay's impeccable reportorial skills and a remarkable degree of engagement, this is an utterly unique and fascinating read. Illus., maps.