The nine paintings by Ellsworth Kelly, completed shortly before his death in 2015 and currently on view at Matthew Marks Gallery, are a posthumous gift to all fans of Minimalism. Rigorously controlled and flawlessly executed, the works are a tour de force that show the dynamic relationships between shape, form and color; depth and density, weight and balance. Hovering between sculpture and painting, they are exemplary studies of the malleability of color and perception. At Matthew Marks through June 24.