The order of colors for karate belt classifications is white, yellow, orange, green, blue, purple, brown, red and black. However, some different forms and schools of karate use their own ranking systems to note progress, which can involve different belt colors.
Karate originated on the island of Okinawa. It spread to the rest of Japan over the early 20th century. Due to resource shortages after World War II, belts became a convenient way of denoting rank. Students could keep the same belt throughout their training and dye it a darker color each time they progressed.
The white belt is the first belt that a karate student wears. It represents the search for knowledge and the beginning of the student's journey. Students wear the white belt until they complete a grading. If they pass the grading test, they earn a yellow belt. They can only wear each belt color after they have completed a test to pass to that level. They can then earn each belt progressively until they achieve the black belt, which is the final belt.
Some forms of karate also use patches and stripes on their belts. This often occurs at the green, blue and brown levels. The patches or stripes also note rank.