Why can red ward off evil spirits?

personal understanding: in ancient times, only blood and fire were naturally visible in nature, which means that red is a symbol of blood and fire. When blood is seen, there must be killing. When fire appears, it can bring warmth and health, and it can also scare away creatures that are harmful to human beings. These are all related to intense upward security, so it will gradually evolve into red to represent good luck and well-being. Since it has been recorded again, people have found that red will make people inexplicably excited, and such excitement will also stimulate people's psychology. This series of meanings are combined to draw a conclusion that red can ward off evil spirits.