You notice the red before anything else: walk into one of the great houses of Pompeii, out of the white southern glare and into the cool of a painted room, and the walls come at you in a deep, saturated, blood-and-wine red so distinctive that the world has simply named the color after the place.
Pompeian red, or rosso pompeiano, as they say in Italy, is a shade you can still order today by that name from a paint chart, the color of the buried city and the ground on which its most famous frescoes seem to float, from the dancing figures of the Villa of the Mysteries, to garden scenes, and little floating cupids.