Let the monochrome and the gesture become their own enterprise of sensation, and the eye adjusts itself to the absence of light in the washes of muddy siennas, dark greens, and burnt umbers. Lynette Yiadom-Boakye’s small painting Underground (2009) and its double Underwrite (2009), in her solo show “Any Number of Preoccupations,” both feature a dark-skinned figure that emerges in low-chroma patches from the murky ground. Could it be the same man in both, one moment wearing an olive sweater, the next a gray-blue shirt? The interiors echo the titles’ prefix as they suggest subterranean light. Under alludes to below, beneath—to what is not seen or represented.