The colour is traditionally white, representing purity, sincerity, peace and initiation. White is also the most difficult to maintain, and keeping it clean trains us in devotion and sincerity. A high degree of cleanliness should always be maintained.
Please note that the Korean flag (Tae Keuk Ki) badge, sewn on the left arm, has the red (Yang) section on top, and blue (Um) section at the bottom. The Union (UK) flag is sewn on the right arm.