An all-black house would look sinister. But when you use this color as an accent, it's more like a black bow tie: the perfect finishing touch. Besides using pure black this way, you can also use very dark shades of other colors. Extremely dark green, for example, "reads" as black and yet adds a bit of mystery that pure black lacks. Try using the darkest shade of whatever color you choose for walls. Creamy white is a great third color.