Long regarded as a building clad only in white marble punctuated with red plaster tiles, niches and galleries have been found in a mid-level tier of the arena, which is undergoing a $26.6 million cleaning and restoration, the Italian news agency ANSA reported Friday.
"They've uncovered complex decorations, floral patterns in polychromatic glory, including azure, ochre, pink and green. We never expected to find such multi-hued decorations, a veritable riot of color," said Colosseum superintendent Rossella Rea.
Under centuries of graffiti and visitor's signatures in the stonework, restorers also found "symbols of ancient machismo and blood lust, as well as erotica," she added.
Construction of the Colosseum, or more properly the Flavian Amphitheater, ancient site of sport and gladiator combat, began in A.D. 72 by Emperor Vespasian and completed eight years later.