[wmks shogun]

I skimmed through the posts to see if this had already been said and I do not think it has, so here is my addition, though I think it is common knowledge:
The origin of colored belts comes to the martial arts world from Judo's found Kano, Jugoro. Kano needed a way to help distinguish students from teachers, so he had the students wear white belts and the teachers wear black. It then occurred to him that a beginning student and an experienced student are not a fair match up and since he wanted Judo to become an olympic sport, he began to add colored belts to show levels of proficiency. Funakoshi, Gichen, the founder of Shotokan adopted concept of belt ranks as well after speaking with Kano about it. From there, the concept of rank being associated with belt color spread throughout the world (Korea got it during the Japanese occupation of Korea, I believe). Today, more colors are added so that a) the road to black belt has smaller more managable steps and/or b) more money coming into a school from belt testing fees (often known as the evil side of belt ranks, especially when there are testing fees for every belt and stripe and some schools have many many more colors and stripes than others).