The Forbidden City is clearly "red", why is it called "purple"?

Last year, I went to Beijing with gay friends and went to the Forbidden City. Standing in Tiananmen Square, I was completely transfixed. I feel like I'm in a TV picture and finally I'm in the heart of China. That feeling is really wonderful.

Go in from Tiananmen Square and go a little further. This is the entrance to the Forbidden City. It is magnificent and imposing. The only drawback is that there are too many tourists, but the Forbidden City is worthy of being an imperial capital with a huge area.

Astronomy and astronomical observation were very popular in Qing dynasty, and everyone liked to use astronomical phenomena to predict fate. The name of the Forbidden City adopts the theory of astronomy. At that time, astronomy divided the universe into three parts, with Polaris Wei Zi in the middle and the center of the universe.

The Forbidden City is the seat of the royal family, so it should be in the center. Therefore, it is compared to the Forbidden City with Wei Zi constellation, which symbolizes the concentration of power here. But the Forbidden City means that it is an important place for the royal family, and it is forbidden for others to get close to it, which gives it a magnificent momentum.

So the Forbidden City is also called the Forbidden City, and the soldiers who defend it are called the imperial army.