Since all the walls in the house are painted white, Catherine added some pops of color elsewhere to liven things up. This yellow door adds so much cheer to the room. The couple also painted a chalkboard under the stairs where they leave eachother messages, doodle when the mood strikes, or work out the occasional math problem.
If you're feeling a little bolder and braver, try a much less subtle use of green and make a real style statement with a bright hit of green somewhere in your home. Here, the emerald green velvet staircase contrasts with the fun wallpaper to create a really exciting and engaging space.