First of all, Dan Shu is ominous, which has always existed. "Zuo Zhuan Xiang Gong Twenty-three Years" records: "Bao Fei and Ye Li were written in the book of Dan." That is, the ancient people recorded the names and places of origin of prisoners with red pens. So many people are taboo about red. If possible, they are generally reluctant to write in red. In the TV series we saw, the ancient word used to kill prisoners was such a scarlet letter. Therefore, the ancients were very taboo to write with red pen, so they didn't want to write with red pen.
The second kind of red stands for supreme power. For example, the Ming emperor read the memorial with a red pen. This color is supreme, and no one can use it except the monarch. This is a color that can't be used casually in the Ming Dynasty. So there will be later teachers reading with red pens. As for whether it comes from the desire for power, I don't know, but teachers usually read it with a red pen. Don't you think so?
Third, China people's love for red stems from our nation's reverence for blood. Therefore, red is often used as a symbol of reverence. For example, our red lantern was hung high during the New Year in China. And our red scarf. Many children think it's military blood. Were you taught this way when you were a child? I am anyway! I didn't know I was cheated until I grew up!
Red is actually the color that many people pay attention to. I don't know if it comes from worship or because of the passion for power. Do you like writing with a red pen?