BLACK PAINT CAN HIDE A MULTITUDE of sins,” says Melinda James, partner at Texas-based M. James Design Group. The offending party? A windowless primary bedroom with concrete columns, beige carpet, and exposed HVAC ducts. Part of the Houston loft she and her work-and-life partner, John Thomas James, purchased to use as a pied-à-terre, the room now boasts multiple coats of Black by Benjamin Moore, plus oak flooring, a brass-and-quartz chandelier, and—as on every other inch of wall space in the apartment—tons of art. Situated on the 17th floor of a modern residential tower, the unit peers out on the Cullen Sculpture Garden, Museum of Fine Arts, Houston, and Contemporary Arts Museum Houston, some of the Jameses’ favorite haunts when visiting the city. Says Melinda: “It’s our escape to be in…