The History of this belt comes from the
Tracy's Kenpo Karate home page
This page contains a brief history of the Kenpo Karate Purple Belt that dates to 1962, when the Tracy brothers introduced Rokkyu (6th Kyu) as the second earned rank in Kenpo karate to replace the one brown tip on the white belt
Purple Belt was introduced to the martial arts in 1962, with the Yellow Belt, when the Tracy brothers created Rokkyu (6th Kyu) in Kenpo Karate. This was the second earned Kenpo rank, and was equivalent to what had previously been "one brown tip" on the white belt for Gokyu (5th Kyu). The old Kenpo Karate Gokyu had required 63 techniques while Purple Belt required 64. And while 63 techniques were the standard set by Ed Parker for "one brown tip" the Tracy brothers were the only ones who actually made it mandatory.
The techniques are the basics for beginning Kenpo, and some forms of karate, and are used as an exercise for physical conditioning. Like Orange Belt, many of the moves have been adopted by aerobics.