Why do you hang red lanterns on the Lantern Festival?

There are many theories about the origin of playing lanterns. A widely circulated saying is that the custom of playing lanterns on the Lantern Festival began in the Eastern Han Dynasty. Emperor Liu Zhuang of the Eastern Han Dynasty advocated Buddhism. He heard that on the fifteenth day of the first month, a Buddhist monk watched the Buddhist relics and lit lanterns to worship the Buddha, so all the gentry and ordinary people hung lanterns that night. Later, this Buddhist ceremonial festival gradually formed a grand folk festival. This festival has experienced the development process from the court to the people, and from the Central Plains to the whole country. During the Kaiyuan period of the Tang Dynasty, in order to celebrate the country's prosperity and people's peace, people tied lanterns, symbolizing "lucky dragons, rich people and strong country" with flashing lights. Since then, the custom of playing lanterns has been widely spread. The first month is the first month of the lunar calendar. The ancients called the night "Xiao", so they called the fifteenth day of the first month the Lantern Festival. The fifteenth day of the first month is the night of the first full moon in a year and the beginning of the Yuan Dynasty. On the night of Spring Festival, people celebrate this festival and the continuation of the Spring Festival. Lantern Festival, also known as Shangyuan Festival, is celebrated by lighting thousands of lanterns on this bright night according to the folk tradition in China. Go out to enjoy the moon, light lanterns, set off flames, enjoy solving riddles on lanterns, eat Yuanxiao, have family reunion and celebrate festivals. The Lantern Festival is also called Lantern Festival. The custom of burning lanterns in the Lantern Festival originated in the Han Dynasty, and in the Tang Dynasty, the activities of enjoying lanterns became more prosperous. Lights are hung everywhere in palaces and streets, and tall lantern wheels, towers and trees are built. Lu, a great poet in the Tang Dynasty, once did this in Watching Lights at Fifteen Nights. In the Song Dynasty, more attention was paid to the Lantern Festival, and lantern viewing activities became more lively. The lantern viewing activity lasted for five days, and the styles of lanterns were more abundant. In the Ming Dynasty, the Lantern Festival will last 10 days, which is the longest Lantern Festival in China. Although there were only three days to enjoy the lanterns in the Qing Dynasty, the scale of the lantern viewing activities was unprecedented. Besides burning lanterns, fireworks are also set off for entertainment. "Lantern riddle", also known as "playing riddles", is an activity added after the Lantern Festival, which appeared in the Song Dynasty. In the Southern Song Dynasty, Lin 'an, the capital, made riddles every Lantern Festival, and there were many people in solve riddles on the lanterns. At the beginning, it was a busybody who wrote riddles on paper and posted them on colorful lanterns for people to guess. Because riddles are enlightening and interesting, they are welcomed by all walks of life in the process of communication.