The ancient Greeks were brilliant sculptors, who were the first to accurately render the human body in bronze or stone. Perfection, defined as understanding contrapposto, was reached at the beginning of the fifth century BCE.
It has often been assumed that the old statues were made of white marble from Paros or the Pentelic Mountains. The absence of color was even lauded as a brilliant abstraction, an aesthetic judgment comparable to the idea that old black-and-white movies have a beauty of their own, and that it is blasphemy to make a colored version of, for example, Buster Keaton’s The General.
Yet, the ancients did in fact paint their sculpture. On many statues, we can still see traces (example); yes, even when we can not discern these traces, our scientists, applying all kinds of modern technology, know how to reconstruct them. According to our standards, ancient sculpture had screaming colors and was absolutely campy. I remember a lecture in Oxford, the introduction to a series of lectures on ancient sculpture, in which people burst out into laughter on seeing a slide with an exquisitely ugly Primaporta Augustus.
Polychromy was also characteristic of ancient architecture. The monuments on the Forum Romanum were made of green, purple, red, or white marble, and grey or purple granite, while the floors were covered with stones that had yellow, green, or purple veins. Exposed to centuries of sunlight, the colors have now vanished, but if you look at the floors of Rome’s medieval churches, which are covered with mosaics made of ancient marble, you get an idea of the splendid colors of the ancient city.
An interesting website, in German and unfortunately with music you’re forced to listen to, on the subject is here.