The Korean Flag is called the "Taeguk-ki" and was adopted in August 1882. The central theme of the flag is that although there is constant movement within the sphere of infinity , there is also balance and harmony.
The flag consist of three parts: a white background a red and blue circle ("the um yang") and the four black trigrams surrounding the circle in each of the four corners.          The Circle in the center is called the "taeguk" and means "the origin of all things in the universe". The red and blue parts of the circle represent eternal duality.
The blue portion of the circle is called the "um" and represents the negative aspects of this duality. The red portion of the circle is called "yang" and represents the positive aspects. The four black trigrams come from the I Ch'ing. The Trigrams also carry the idea of opposing and complimentary force. Each trigram consist of three parallel lines some of which are broken and some of which are unbroken.  In the upper left hand corner is "K'un" which consist of all solid lines and represents heaven, east, and spring. In the lower right hand corner is "K'on" which consist of all broken lines and represents earth, west, and summer. In the upper right hand corner is "Kam" which consist of one solid line surrounded by two broken lines and represents water, north, and winter. In the lower left hand corner is "I" which consist of one broken line surrounded by two solid lines and represents fire, south, and autumn.