My daughter did her new baby's room in Peter Rabbit. It is in browns and greens. I sponge/feather painted the top half and papered the bottom half of the walls. The paper was in Peter Rabbit, with a nice matching border print. Then he got older, and she used the same painted walls on top but added paper to the bottom with a fishing scene, and added a border with the same theme. I made him a quilt in the same fishing theme. He gets to go fishing with the Daddy and he has already caught his very own fish!!
But, the trend is to use brighter primary colors. I did my son's room in red. blue ,green and yellow.Both rooms turned out nice.