We are about to paint our bedroom too. We chose a green that I think might be nice, but I'm not committed yet. I can tell you though, if you bring home a bunch of samples and hold them against the wall you can narrow down your choices pretty quick. Also, once you paint, keep in mind that it may appear darker once the whole wall is covered. Home Depot sells tiny sample size paints that will let you paint a section of wall just to see if you like the color. You could narrow it down to a few choices and try each one on a different section of wall. Then see how they look in natural daylight and at night to see which one you like best.
One last thing, they say that darker paint doesn't make a room look smaller, but I think it does. If you like an open, airy feel, go with a lighter color.

Oh, also, you have a chance to do something creative with that nook that follows the line of the roof. I don't know if accent walls are an out dated design concept or not, but that might be fun to play with in that area.

I would also consider painting your walls, ceiling and all angles the same colour.
This prevents your space from looking too broken up and works well to create flow in a space with many angles.
Have fun with it!
Caroline

i think i will paint green walls, but i'm not sure yet. i also dont know where my bed will be.