Also written 暈繝. Also *ungen zaishiki 繧繝彩色, lit. "rainbow coloring." A method of coloring employed originally in painting and the decorative arts to lend a sense of weight or three-dimensionality to the object, but which later became more ornamental. Two or more graded bands of one color are laid side by side, usually beginning with the lightest colors on the outside and ending with the darkest on the inside. However, the opposite arrangement, darker to lighter, is also found gyaku-ungen 逆繧繝. Simple decorations have two or three bands and more complex ones may have five or six. Each variation of color is clearly distinguishable and the bands are not blended together. Also called danbokashi 段暈.
This technique was employed in China as early as the 5th-6th century, and is thought to have been influenced by Central Asian mosaic techniques in the decorative arts and weaving crafts tsuzureori 綴織. As a rule, four basic color patterns -- blue, green, red and purple -- were commonly employed together. In Japan, rainbow-like arrangements of colors can be found in the arts as early as the 7th century, but it was not until the 8th century that true, four-colored ungen zaishiki was employed on Buddhist statues and paintings, architectural ornamentation, and the decorative arts. During the Heian period, this coloring method evolved into an extremely fine, delicate decoration technique.