Using a fun pattern with multiple paint colors on one feature wall is a nice way to add a playful factor to your child's space.
Adding paint inside the bookshelves makes the decorative items pop, but the true star of the show is the striped ceiling.
If you're nervous about adding pattern to the ceiling, how about a nice dash of color such as this bright pink?
I love this idea of adding white text over black paint. The room shown here has the alphabet written out, but you could customize your wall to fit your child's personality.
I'm certain the car and road shown on the left wall in this image are decals, but the orange line around the perimeter of the room adds a nice splash of color to this otherwise modern kids' space.
The color scheme of this room is calming, but the pattern on the wall and the red details keep it from getting boring. It's a space your child could easily grow into.