Personalized House Numbers. The images shown are Shu Sugi Ban, which is a Japanese name for an ancient technique of charring wood with fire. This was used by many cultures around the world as a natural wood preservative. There are many other color combinations available. I use a light reflective paint if you choose a white paint, for the numbers, on a color background. So, a white on blue scheme would be white reflective paint in the numbers with a blue painted background.