It's true; art imitates life.
Look closely at the picture above.
It's a Greek statue, and judging by the pose, it's from the Classical age of art in ancient Greece. ****EDIT*** This is not a Greek statue. It is Roman, of Caesar Augustus. The Romans also painted statues, so it still fits the scope of the post ***
When you think Greek statues, or ruins, for that matter, you picture something like the statue on the left.
Too bad the statue on the right is the accurate representation of what the Greeks did.
Many Greek ruins, not just statues, were found with traces of paint on them when excavated. But, the archeologists who were digging up the painted artifacts didn't like that they were painted. They had been studying ruins in cities like Athens for so long, they were used to the bare stone look of ancient Greek architecture.
In fact, architects of the time copied classic Greek buildings. Look at all the plain limestone buildings with columns you still see in cities today. Banks, armories, post offices and state houses copied the Greek way quite a bit.
But the truth is, the Greeks painted everything. All their statues were painted. The Parthenon, The Acropolis, The Agora, all were painted in bright colors. And not only were the statues and bas-reliefs painted, but the columns would be painted as well.
With time, the weather and the environment took care of the paint. Mostly.
You can still see some original Greek statuary in museums that still has the original paint on them.
And that's no thanks to the archeologists in the 17th and 18th century who so detested the thought of painted statues that they'd clean the remnants of the paint off.
Once you start imagining ancient Greek statues and buildings brightly painted, you'll never think of the ancient Greeks in the same way again.