Within the seventies, lower ranks (kyu) started to be supplied colourful belts to show development. This proved for being commercially viable and coloured-belt programs had been adopted in several martial arts degree mills (also called McDojos and belt factories) as a means to crank out added income. Encyclopaedia Britannica's https://www.etsy.com/listing/1423187891/personalized-karate-picture-frame-karate