Primary Colors

With a palette of around 17 million colors at his fingertips, today's computer artists have virtually no limits to their basic materials. It's difficult to imagine, then, how painters of previous generations coped with a more limited range of hues. According to the Roman historian Pliny, artists in classical Greece, for instance, used only four colors: black, white, red and yellow. Pliny added that the restricted palette was the proper choice for sober-minded painters. Whether the artists of antiquity agreed is not recorded.

In his new book, Bright Earth: The Invention of Colour (Viking; 434 pages) science writer Philip Ball...