Rank in Judo judo association. For a rank to be recognized, it must be registered with the national judo organization or the Kōdōkan. In Japan, the use of belt colors is related to the age of the student. Some clubs will only have black and white, others will include a brown belt for advanced kyū grades and at the elementary school level it is common to see a green belt for intermediate levels. In Europe the belt system is white, yellow, orange, green, blue, brown and black for both senior and junior practitioners. Judokas who have attained the 6th Dan may also use
Orange (colour) it contains arsenic and is highly toxic. It was also used as a fly poison and to poison arrows. Because of its yellow-orange colour, it was also a favourite with alchemists searching for a way to make gold, in both China and the West. Before the late 15th century, the colour orange existed in Europe, but without the name; it was simply called yellow-red. Portuguese merchants brought the first orange trees to Europe from Asia in the late 15th and early 16th century, along with the Sanskrit "naranga", which gradually became part of several European languages: "naranja" in Spanish, "laranja"