In Chinese New Year superstition, red is traditionally associated with luck and prosperity.
Red appears throughout Lunar New Year celebrations in decorations, clothing, paper cuttings, lanterns, and envelopes containing money. In Chinese culture, it is linked with happiness, vitality, celebration, and protection from harmful forces. Red envelopes, called hóngbāo in Mandarin, are commonly given to children and family members during festivals and other important occasions.
The association also appears in the legend of Nian, a monster said to fear the color red, loud noises, and fire. That story is one folkloric explanation for New Year customs, although the modern festival combines many historical traditions.
Red is not universally lucky in every Chinese context. White, for example, is strongly associated with mourning, and color meanings can vary by occasion. The New Year connection is therefore a specific cultural convention, not a claim that red has an objective supernatural power.