Colors and shapes used elsewhere also stimulate babies. "Patterns of colors and variety of colors help stimulate growth of depth perception," Krull says. In classrooms, the philosophy is to keep the floor and wall palette neutral to avoid overwhelming the space with color. "We either do warm whites or a light pastel as opposed to primary colors. The theory is the color should come from the children and objects -- colorful blocks, beads, children's artwork -- as opposed to putting things like that against a multipatterned wallpaper," says Louis Torelli, co-founder of Spaces for Children, a child care design firm in Berkeley, Calif.
A neutral color isn't as necessary in the nursery as it is in the classroom, but the idea of keeping the visual landscape enriching yet clutter-free can be applied in the home. "You don't want so much stuff out there that it overwhelms the child and turns him off," Torelli says. "If he sees everything he has in his room all the time, it becomes white noise. The child needs novelty within sameness." Torelli recommends achieving this by setting up a combination of open storage and closed storage. This way, a child easily can choose from among the few items displayed on the shelves, all of which he can see at once. Then, parents simply swap out those toys and books every so often for the ones tucked away in a cabinet.