Never ever do this. We are uncertain who introduced these tiles in the first place. Backgrounds like these are extremely popular, especially in webdesignschools in Europe. This is how your driveway should look. Or awarded sites at Geocities.

It is nice with a beautiful bathroom tiled like this. But you do not want to flash your toilet to the viewers of your site. Add the forbidden colour of first lesson to this background, and you can expect getting calls from your therapist. Go on to see the correct background.