The History of the Red and White belt
Many aspects of karate are inextricably linked to it's older sister Judo.
Judo was established in 1882 by Professor Jigoro Kano. He named his training hall the "Ko-do-kan," or "a place to teach the path."
Based on classical Ju-Jutsu, Jigoro Kano's new art eschewed striking in favour of close quarter grappling, throws and restraints. The core of this system was the "maximum efficient use of energy". A philosophy not just at the heart of many martial arts but a principle useful in many facets of life.
What Jigoro Kano had created went beyond mere technique to include principles for improving the self. To show this, he replaced the suffix justu (technique) in the word "ju-jutsu" with the suffix do (path) and Judo was born.
Karate also follows this precept and you can train in both Karate-Do and Karate-Jutsu.
Though Judo is considered by many as purely a "sport", most enlightened martial artists will accept that throwing a person is one of the most highly skilled and difficult tasks to perform in the martial arts.
In the early 1900s the striking art "Kara-Te" was created as a general name for a variety of Okinawan (and later Japanese) "Te" combat arts. When registering their new Karate art with the government the early Karate Masters borrowed (stole?) aspects of the already established Judo to help gain their much needed official recognition. One aspect they borrowed was the use of specific training suits (gi) and the rank/belt system.
Around 1930, the Kodokan created a new belt ("obi") to recognize the special achievements of high ranking black belts.
Jigoro Kano chose to recognize sixth, seventh, and eighth degree black belts with a special obi made of alternating red and white panels (kōhaku obi - literally translated as "red and white belt"). The white color was chosen for purity, and red for the intense desire to train and the sacrifices made. The colors red and white are an enduring symbol of Japan, and they have been used in Judo since Jigoro Kano started the first Red and White Tournament in 1884.
In 1943 the Kodokan created the optional all red belt to recognize ninth and tenth degree yudansha.
The selection of red-and-white colored belts to distinguish the highest ranks may have also been based on a simple cultural preference, according to Meik Skoss, a noted martial arts historian and author of numerous articles about Japanese martial arts. Japanese typically divide groups into red and white sides, based on a pivotal historical event, the Genpei War - a dispute between two rival clans, the Genji and Heike. The Genji used white flags to identify their troops on the battlefield, while the Heike used red flags.
The "kōhaku" obi is often worn for special occasions, but it is not required to be worn at any specific time and the black belt remains the standard obi for all the dan grade ranks.
Though not common in karate, the kōhaku obi is accepted as an option to the standard black belt for high grades, though there is some variance as to when the plain red belt is awarded. Originally the Judo red belt was for 9th and 10th Dan grades, but in Karate it is often used for 8th Dan grades as well.
The decision as to whether the "Master" belts are worn varies according to karate style and association.
The kōhaku and plain red belt are not the only "unusual" belts available in the martial arts, high graded Ju-Jutsu Masters wear a midnight blue belt!
There is also a wide range of "exotic" belts available (mainly in the USA) which are often used in new arts such as XMA (Xtreme Martial Arts).