Color, as the most prominent visual element, has played an important role ritual system. This article attempts to use the color in the painting "Walking Chariots" as a case study, hoping to reveal the hierarchical system, cultural integration, and daily marriage of Tang Dynasty society, and help us understand how the spirit of Tang Dynasty's ritual system was reflected in specific ceremonial occasions. The "Walking Chariot Diagram" is divided into two parts, the right part is large, the left part is small, and the right part is Emperor Taizong of Tang (supreme yellow); On the left side, in order of rank, there are officials from the Ministry of Rites (third grade crimson), Ludongzan (national dress), and translators (no grade white). Lu Dongzan, dressed in his own country's formal attire, expressed the cultural integration policy of the Tang Dynasty's official policy of "valuing China since ancient times, belittling barbarians, and loving them as one". Marriage, as a great ritual of human relations, was understood by Tang Dynasty people as the basic content of yin and yang in heaven and earth, and was used in color.