Re-creating the hues of long-extinct creatures has always been a job for art, not science, because pigments in skin and feathers are lost as tissues decay. Andrew Parker, a biologist at the University of Oxford in England, has a way to get some of the color back. The secret is that not all animal colors come from pigments. In bug exoskeletons and butterfly wings, microscopic layers of tissue reflect and combine light to create intense visual tones. Occasionally, fossils form in such fine-grained rock that these delicate layers are preserved. Parker and David McKenzie, a physicist at the University of Sydney in Australia, used an electron microscope to examine alternating layers in the exoskeleton of a 50-million-year-old blue beetle. Using a computer model, the researchers deduced that light rays bouncing around in those layers would combine to produce blue turquoise light, the exact color reflected by the actual fossil. A similar analysis could be extended to other ancient bugs, trilobites (such as the one at right), and crustaceans. Scales can also be tinted with iridescent colors produced by ripples on the surface, “so you might be able to determine their color from just an impression left by the fossil and not the actual thing,” Parker says. If so, he could authentically colorize some long-extinct fish, snakes, and reptiles—and yes, even dinosaurs.