Using bathrooms can be an everyday nightmare for children attending Japan's public schools where the restroom is often considered dirty and smelly.

But a professor in western Japan has come up with an eye-opening way to blow away the stench.

Machiko Yamashita, a professor of environmental life studies at Otemae University, conducted a seven-year research project in which she and her students repainted the walls of 200 restrooms at 21 public elementary and junior high schools in Nishinomiya and Amagasaki, both in Hyogo Prefecture, in several variations of red, blue, green and orange.