Which country's flag contains a red and blue ying-yang symbol in the center of a white field?

The distinctive banner with a central red and blue circle is the national flag of the Republic of Korea. Known officially as the Taegeukgi, its design is rich with symbolism rooted in traditional Taoist philosophy. The white background of the flag is a traditional color in Korean culture, representing peace and purity. In the center is the Taegeuk, a symbol representing the balance of the universe. The upper red portion signifies the positive cosmic forces (yang), while the lower blue portion signifies the opposing negative cosmic forces (um, the Korean equivalent of yin).

Surrounding this central symbol are four black trigrams, one in each corner. Each trigram, or gwae, also represents a fundamental concept of balance and harmony. The three unbroken bars in the upper-left symbolize heaven, while the three broken bars in the lower-right symbolize earth. In the lower-left, the trigram for water is depicted, and in the upper-right is the trigram for fire. Together, all the elements on the flag—the white field, the central Taegeuk, and the four trigrams—embody the ideal of a nation in perfect harmony with the universe.