“When I didn’t know what color to put down,” said Henri Matisse, “I put down black. Black is a force: I use black as a ballast to simplify the construction.” Matisse is often hailed as the greatest modern colorist, but his practice was heavily grounded in the use of black and white—the achromatic colors. In Goldfish and Palette (1915), for example, ochre, red, and lavender read like held notes within a symphonic structure of black, white, and gray. And in the interior of the mid-century Chapel of the Rosary in Vence, its plan devised by Matisse, stained-glass blues and yellows seem to sing to the quieter black-and-white ceramic tiles. In this exhibition, 25 artworks—as well as drawing, prints, and books—delve into Matisse’s secret strategy: non-color. —E.C.