One of the first things I had to do once we bought our house was to give my daughter a bedroom painted and designed exactly as she wanted. She went to her Nana's house for the weekend and I got to work. She wanted a princess bedroom in all pink and purple - her favorite colors. The room gets enough light that this wasn't overpowering. I later added all white furniture to lessen the impact of such a colorful room.
I started by drawing each princess and creating a stencil from it. I probably could have found some stencils online, but where's the fun in that? I did silhouettes to again lessen the impact of using such bright colors, Same idea with the two white stripes.