In total darkness, we cannot see things even if they are there. We can only see things in bright places. We see things because light strikes them and is reflected back into our eyes. In other words, the reflection of light has something to do with how we see things.
Clouds also reflect light. Clouds also reflect light, and we see clouds because light enters our eyes, but the way clouds reflect light is a little different. Because clouds are made up of many small particles of water and ice, they do not reflect light in the same direction, but in various directions. This is called diffuse reflection. Diffuse reflection works to make objects appear whiter by eliminating their color. Clouds appear white because light scattered here and there enters the eye. This is the same reason why snow looks white.