The second step is to choose the material and color matched to the theme of your child's room. Buy fabrics, wallpaper or border paper is to reinforce the theme that you create. Select primary colors in tune with the rest of the room. Then choose a background color that will be used on walls, ceiling, and floors. Use a cloth when you design a child's room to guide you in finding your inspiration. Set the color of all the elements in the room to blend and can reinforce your theme. Kids Room.