One other comment that I meant to make earlier regarding your brown belt comment. The Japanese term for first degree black belt is shodan. There are multiple nuances to this in translation as there are in many Japanese words. Sho can be translated as first or primary. Dan can be translated as step or level. First step or primary level.
The dan rankings and belt system is only about a century old. It was initiated by Jigoro Kano- the founder of Judo. When Judo had grown to the point that Kano san could no longer know each student's level of advancement personally, he needed a device to cue him to that student's level to avoid injuring the person. That's its only purpose.
The depiction of the black belt as an awesome killing machine is a Western phenomenom. The true meaning of shodan is that you have now reached the physical, mental, and emotional point where your instructor can finally begin to teach you without an inordinate risk of grave injury. The various colored belts were added in Japan later for CHILDREN'S classes. Very few dojos in Japan use colored belts for adult students.