Why do people decorate in red during the Spring Festival?

Speaking of red decoration, there is a little story.

Because there is a legendary monster named Nian who came down to eat people, which makes people feel uneasy. As a result, the jade emperor put him in a prison in heaven. From then on, he hated human beings very much. Later, the Jade Emperor felt sorry for him and allowed him to go down to the earth to look for food every New Year's Eve. Man has found a way to deal with the year when he is afraid of red.

I am afraid of explosion, because red is an auspicious color, so at this time of year, people will make some delicious things, such as couplets and window grilles, lanterns and blessings, all of which are red.