The ITF ranking system consists of six solid color belts; white, yellow, green, blue, red, and black.
Coloured belt ranks are defined as follows (from lowest to highest rank):
|10th Kup||White - Signifies innocence, as that of the beginning student who has no previous knowledge of Taekwon-Do|
|9th Kup||white with yellow tag|
|8th Kup||Yellow - Signifies the earth from which a plant sprouts and takes root as the foundation of Taekwon-Do is being laid.|
|7th Kup||yellow with green tag|
|6th Kup||Green - Signifies the plant's growth as Taekwon-Do skills begin to develop.|
|5th Kup||green with blue tag|
|4th Kup||Blue - Signifies the Heaven towards which the plant matures into a towering tree as training in Taekwon-Do progresses.|
|3rd Kup||blue with red tag|
|2nd Kup||Red - Signifies Danger, cautioning the student to exercise control and warning the opponent to stay away.|
|1st Kup||red with black tag|
|1st "dan"||Black - Opposite of white, therefore signifying the maturity and proficiency in Taekwon-Do, also indicates the wearer's imperviousness to darkness and fear.|
The reason for nine black belt degrees is that the number nine is not only the highest of the single-digit numbers, but also is the number of three multiplied by three. In the Orient, three is the most esteemed of all numbers. The Chinese character for 3 is three horizontal lines, one above the other. The bottom line represents earth; the middle line represents mortals; the upper line represents heaven. It was believed that a man who could unite the three realms in himself, would aspire or be reborn into a king.