Powder rooms are small; dark colors can make them look like a cave. If you don't like dark, chose a color lighter that what you have now.

Pale blue.

Benjamin Moore - Elephant Tusk

That faucet is scary. How does it work?
I don't like dark walls in here... makes it look like an alien abduction examination room.
I would go with white walls.

That chocolate brown color is not on trend anymore. Try something softer. Even a gray tone will work with the flooring you already have.

SW Really Teal

I know it's more work/money but have you thought about a great textured wallpaper? Say a faux wood or grasscloth? A mural would look smashing too with the glass sink! Just using paint seems too slick with all the glass, some contrast is needed. Love the floors!

Oh, and don't be afraid to go dark in a powder room. Bring the color up on the ceiling too. It will have a wonderful "jewel box" feeling.