Minecraft wiki entry for Making_nice_floors, associated text: You can use this rainbow-like pattern to make a very colorful floor. Although it looks the best for at least a 7 x 7, it can be accommodated to smaller sizes. For bigger sizes, you can add more colors, such as orange and purple. The first grid here shows how you can use this rainbow flooring for a 7 x 7 floor, and the second grid for a 12 x 12 floor.