The belt system used by ITF Taekwondo is designed to show the progression of a student's training by using different colours. Once the student attains black belt level, the grade is shown by stripes or numerals on the belt.
All belt colours have a meaning, used as a metaphor for progression of training.

White : Signifies innocence. No previous knowledge of Taekwon-Do, as that of a beginner student.
Yellow : Represents the earth from which the plant sprouts and takes root as Taekwondo foundation is being laid.
Green : Represents the planet's growth as Taekwondo skills develop.
Blue : Signifies the heaven towards which the plant matures into a towering tree as Taekwondo training progresses.
Red : Signifies danger, cautioning the student to exercise control, and warning an opponent to stay away.
Black : The opposite of white, therefore signifying a maturity and proficiency in Taekwon-Do. It also indicates the holder’s imperviousness to darkness and fear.