The moon shines by reflecting sunlight, and the earth revolves around the sun; The moon goes around the earth. Therefore, the distance between the moon and the sun often changes. The closer to the sun, the yellower the moon is; The farther away from the sun, the whiter the moon. Coupled with the thin atmosphere and the interaction between ice crystals, water droplets and various impurities and light, the phenomenon that the moon is sometimes yellow and sometimes white or produces purple, blue and cyan is formed!