• Powder rooms. Powder rooms are like the baby of the family — they can get away with anything. Go dark, go bold, go super over the top. They can handle it, and you will still love them for it. Because of their small footprint and because of the small amount of time you actually spend in a powder room, it's a good place to experiment with dark paint. As long as the lighting you pick isn't dinky, the dark color will help the small space feel elegant, dramatic, and sophisticated.
• Nurseries. Have you ever tried to get a baby to go to take nap? Exactly. It's tough stuff trying to convince them that the world's not having all the fun without them when the room is bright as day. My baby's nursery is kind of the best of both worlds. During the day it gets a fair amount of light, so when we pull up the shade it's great for playing. But when the shade is down, the deep navy walls make it feel like night.
• Basements. Most basements are already dark places, reliant on artificial light. Embracing the cave-like atmosphere, and making it cozy, is one way to make the most of this space. Marya and Rick's basement is one of my favorite examples, because even without a finished ceiling, it feels welcoming and relaxing. Add colorful accessories to lend a dark basement some light.
(Images: Ty Larkins Interiors, Leah Moss: Saf's Pint-Size Personal History, Leah Moss: Marya & Rick's :Layred & Luminous Arlington Retreat)