In most Japanese and Korean martial arts, member wear a long colored cloth (belt) around their waist.
They are for the most part long enough to be wrapped twice around there waist and then tied in a square knot,
with 10 to 15 inches hanging from either side of the knot. Before the 20th century, most belts were white,
but since students were banned from washing their belts, belts grew gradually darker through years of accumulated
sweat and dust. When the colored belt structure of rank was adopted, it was agreed so that the belt color
became darker as the student advanced in rank, ending with the black belt, the highest level of expertise.
Black Belt Color of belt worn in the Japanese, and Korean martial arts. Black Belt is generally recognized as an expert.
Belts vary according to style and kind of martial art, in some schools there is only a small colored tip
on the end of the belt to show rank. In each instance the color represents a different recognized rank,
for example, brown in Japanese karate corresponds to red in Korean tae kwon do. The most common colors
used in martial arts are white, yellow, orange, blue, green, purple, brown, and black.

In most styles, there are 10 degrees of black belt, called dan (rank degree), in which the latter five are honorary.
In some styles, the grand master, a 10th degree black belt, wear a red belt.
Judo black belts are usually awarded by a national governing body whose standards are relatively high and
competitive with that of other international bodies.