Designers Lucien Rees Roberts and Deborah Hancock established a monochromatic scheme in the family room. The space owes its allure to its seating’s variety of forms and textures: velvet-swathed B&B Italia sofas, woven Designtex fabric on a Gio Ponti chair from Fred Silberman, and a hide-covered Harvey Probber armchair. Overhead is Jean de Merry’s Lumière chandelier.