There are ways to do navy well, in any room. Regardless of which room you're considering, make no mistake about it - painting your walls navy is a bold choice, and leaves you with a dramatic look.
The first room I lean towards when it comes to dramatic impact is a powder room. This is a room that is smaller than any other in your home and people spend the least amount of time in. So if you are hesitant to commit to color in your home yet want to try it out, this is the room to do it in. You can go dramatic on the walls or ceiling, or both! Check out this magnificent powder room
You could either do wallpaper on the ceiling, or a stencil. I would likely lean towards a stencil since it's a small space and would be easier to lay the stencil, paint, and be done.
When it comes to dinning rooms, you could go all dark, which is very intimate once the lights are dimmed and candles are lit. But if you want to keep some brightness to the space, you could have the best of both worlds
I love this dinning room. It's crisp, clean, and a great balance of modern and contemporary, with a hit of traditional. Check out the silver leaf ceiling - LOVE. And the chandelier is amazing.
Moving to the sleeping quarters, I would always pair navy with a camel / brandy brown color - the combo of the two is nothing short of classy and sophisticated, while incorporating the white keeps it from being over the top and 'stuffy'
Last but certainly not least, is a main bathroom. I'm not sure I would do this color in a smaller main bathroom, actually I'm confident I wouldn't because we have a smaller main bathroom and the previous owners painted it chocolate brown. It doesn't work for me, personally. This bathroom however, looks great. Definitely makes this a more gender neutral bordering on masculine room, but I never have issue with that.
Life is too short to never at the very least try something bold. So don't be nervous...it's just paint.
Better to have painted and lost than never to have painted at all!