Accent color for living room and dining room?

Our house has an open flow between the living room and dining room. The paint is a pale, powdery blue/gray color. All wood work is white. Carpeting is in the same color family, just a little darker. I'm trying to decide on an accent color that will bring some personality into the space. One of my plans is to hang boxes on the wall to display small items and put wall paper in as their backings. I'm not really sure what color(s) to go with though. Any input is welcomed. Reference pictures, too!