Interior Inspiration: Dark Walls

I'm usually drawn to really light and airy spaces, just take a look at my home inspiration on pinterest and you will quickly notice a high percentage have clean and crisp white or off-white walls. So I was a little surprised when I found myself gravitating towards rooms that are dark and moody lately, see a few of my faves below. What do you guys prefer light or dark wall colors? And would you have the guts to paint a whole room in a deep shade?
Image sources: 1. via Crystal Gentilello 2. via Interior Design Sense 3. via Yatzer 4. via Ab Chao