Colours, not white

At the Glyptotek in Copenhagen some of the heads of the Roman or Greek marble statues, or rather casts of heads from said statues, has been painted in realistic colours. That's not just a fancy idea, but a way to show how the statues looked originally, as they were painted to look more lifelike when they were created. The paint has been washed off over time giving us the impression that they were all white. On the photo you can see a bust of Caligula in white and colour.