This is called Attic Window pattern. Shadow Box is a little different. I would use a dark and a medium shade of one color for the 'windows', something that goes along with the center fabric. Bears will be cute for this pattern!
p.s. use this link and look at the second picture for a sample of shadow box pattern. Hope you don't mind this. Just trying to be helpful.
http://www.quiltingboard.com/t-139276-1.htm