For me, fabrics are the thing, so when we were building, I selected fabrics for window treatments in the rooms and then pulled the paint colors from there. It would be helpful if you had some direction to go in. To me, paint colors are integral to decor so I knew I couldn't just pick a couple of colors and go with it.

But other people are different so they may use another approach that works for them.

Try finding an inspiration piece for each of the main rooms....maybe a counter or tile in the kitchen, a piece of art or a picture of a room you like for the living room, a bedspread for the bedroom and pull your colors from there.