I have always been drawn to rooms using a monochromatic color scheme. Some may shy away from this pallet because they see it as flat and boring. Some may also think its the easy way out of designing a space. I beg to differ and see it as a challenging application where it can be difficult to achieve perfection. If really done well it's never flat and boring. Mixing textures, patterns, and color saturation keeps things interesting. Just look at the examples above, all are monochromatic schemes that have interest and life!
Images: Timothy Whealon, Jennifer Flanders, Elle Decor, Mary McDonald, Mary Drysdale