At the Pilgrim Hall Museum Designer Showhouse in Plymouth, Massachusetts, interior designer Richard Eustice kept the dining room perimeters clean white. “The architecture is so strong that it doesn’t require any highlights on the decorative ornamentation,” he says. The floor is grounded by a sisal rug bound in navy blue tape. Grouped into a dramatic niche above the fireplace are five oversized blue-and-white 19th-century Chinese export porcelain jars.