LONDON—The iconic pure white of ancient Greek sculptures makes it difficult to picture them in any other way, but new evidence suggests that the Parthenon temple’s statues and friezes were originally colored. Researchers at the British Museum say they have detected tiny traces of blue paint on the building's statues and friezes. Although only a few hints of a pigment called Egyptian blue have been detected so far, experts believe the original coloring would have included red, along with highlights of gold. At the same time, the original marble still showed through white in places.   

At the museum, an imaging technique called photo-induced luminescence was used to detect microscopic specks of pigment. When red light is shone onto the molecules of Egyptian blue, they absorb it and emit infrared light. Seen through a camera sensitive to infrared, any parts of the marble that were once blue appear to glow. So far, the blue has been found in a few places, such as the belt of the messenger goddess Iris from the temple's west pediment.

Read more at the Decoding the Heavens blog.