Why do clouds appear in different colors?

The color of a cloud is determined by the amount of reflected light. The color of clouds in the morning and evening is due to the scattering of light that is easy to scatter after sunlight passes through the atmosphere, such as blue light, and the rest is colored light with the same wavelength as red light. Because of the different thickness and density of clouds, the amount of light reflected by clouds is different, which makes clouds appear different colors. Clouds are opaque because there is an interface between small water droplets (or small ice crystals) and the air, which produces reflection. At the same time, there is a lot of dust in the clouds, so they are opaque.