There, beneath five centuries of grime from smoky candles, incense, glue and assorted retouchings, he found color-fresh, radiant, vivid color. It was, says Gianluigi Colalucci, director of the Vatican Museum's Painting Restoration Laboratory, "like opening a window on another world."

After four years of painstaking work, the first stage of cleaning the Sistine Chapel has been finished, revealing a dazzling Michelangelo who, contrary to his traditional depiction as a shadowy, tenebrous painter, was a bold and brilliant colorist.