Why do artists always seem to have the blues? Since time immemorial, blue has held a special place in art history, evoking the loftiest sentiments, the most aristocratic pedigrees, and the profoundest spirituality. As a material, blue pigment has itself been a fetishized commodity, serving as everything from a prized color for Medieval monks to the point of obsession for the painter Yves Klein. Many artists have tried to explain the hue’s allure—Fauvist painter Raoul Dufy once said, “the only color which maintains its own character in all its tones,” for instance—but, in fact, blue has had a wide spectrum of meanings over time. Here are five ways the color has been used throughout art history.