Neutral interiors can be a beautiful, restful thing. Done wrong and your left with an overly vanilla and drab eyesore.
Here are neutrals that have it right:
The black drapery hardware, iron canopy bed, and thick black frame all add just enough contrast to create some depth in the space.
Leopard or other animal patterns are a way to do neutral but still add a lot of interest.
Mixing textures is another surefire way to add dimension to a space that has a lot of color in the same value.
Another example of mixing texture – the sisal, metal console table, iron lamp, and wood chests. If all of these pieces were in wood, you can imagine how the space might look more drab.