The majority of the main floor walls will be a light gray. I like doing a bold color accent wall, I get too bored if all the walls are the same color. Plus, we just bought dark gray living room furniture and I think it will pop nicely against 2 plum accent walls.
I was playing around on Sherwin-William's site (which is awesome, btw) and came up with the below color pallete. The green will of course be a decor accent type of thing, unless I get brave enough to use it in the 1/2 bath, but it's a bit outside my comfort zone lol
The gray color on the trim will be the main color.