Throughout history, not all robes are yellow. In the pre-Qin period, the Emperor of Heaven was not so particular about the color of clothes, and there was no unified requirement. Since the Qin dynasty, color has been very particular. Qin Shihuang believed in the theory of five elements, because Qin replaced the Zhou Dynasty with fire and water, so Qin people highly respected black. You see, the royal family of the Daqin Empire and the sharp soldiers of Qin Jun are almost all black. Qin Jun square was dark, which really gave people a sense of suffocation.

Qin Shihuang also wore a black dragon robe when he ascended the throne. The popularity of yellow robe began in Sui and Tang Dynasties, when "yellow is precious" was advocated. According to the Six Classics of the Tang Dynasty, "Emperor Wendi of Sui wore a yellow robe and a silk scarf to listen to the DPRK. Since then, the son of heaven has been wearing red and yellow robes, while his subjects "still wear yellow clothes". "

The real prohibition of yellow among the people was in the Wude period of the Tang Dynasty. Tang Gaozu tang gaozu didn't want to wear yellow robes with ordinary people, thinking that this would be detrimental to the majesty of the son of heaven, so he issued an imperial edict prohibiting ordinary people and soldiers from wearing red and yellow clothes. From then on, "yellow robe" became a symbol of imperial power, and Song Taizu Zhao Kuangyin, the founding emperor of the Song Dynasty, became emperor by "wearing yellow robe". When Zhao Zhen arrived in Song Renzong, it was also stipulated that ordinary people should not use yellow robes as the base or make patterns.

Since then, not only the yellow robe is unique to the emperor, but also the yellow robe is dedicated to the emperor. Because the robe is embroidered with dragon-shaped patterns, the yellow robe is simply called "dragon robe".