Why in Zigui County, the coffin in Guizhou Town is red, while the coffin in old maoping town is black?

The old man said that Zigui used the red coffin because he was moved by Qu Yuan's light, because it seemed that only royalty could use red at that time. Zigui County is the hometown of Qu Yuan, and Quyuan Town in Guizhou below is the hinterland of Zigui. Maoping town uses black because the county seat moves eastward, and the language and traditional habits are closer to the downstream areas, but only a few. There are also some villages near Badong County that are dark, and there are Zigui red ditches. Badong across the ditch is dark, such as Meijiahe Town. Generally speaking, most of Zigui is red, and more than 90% is red.