A growing number of Japanese schools are adopting the "color universal design" system to ensure education materials meet the needs of people with color vision deficiency.
About 3 million people are believed to suffer from color blindness in Japan and activists are calling for greater educational support, with adoption of color schemes that can be easily identified by people with all types of color vision.
At Tonohiraga Elementary School in Matsudo, Chiba Prefecture, a teacher was explaining the stroke order of kanji on a blackboard using specially designed chalk in vermilion red, yellow, blue and green introduced last year.