“The single most important lesson of architectural color is that every color only appears to be what it is relative to its surroundings,” explains Donald Kaufman, the famed color consultant. This is a lesson long known to artists who value gray for its supporting role—in the Renaissance gray was the preferred portrait background to emphasize the richness of the sitters’ costumes, while the Impressionists and Fauvists, for all their love of color, often used gray to make their other colors spark with life.