If clouds are white, then why do they become dark gray before the rains?

Weather of Arabia - It is known that most of the clouds that we see in the sky are white in color, but rain clouds are usually dark gray, so why do clouds become dark gray before rain ?

How clouds form

The air around us contains water in its gaseous form (water vapor), and when the air near the surface of the Earth heats up, it starts to rise, taking the water vapor with it, and as the air rises higher in the sky it cools, causing water vapor to condense on existing dust particles In the atmosphere (condensation nuclei), then water droplets and ice crystals unite together, or combine with each other, to form clouds .

The reason for the white clouds

Unlike atmospheric particles that scatter blue light more than other colors, making the sky blue, small cloud particles scatter all spectrums of light (which together make up white light) equally, so this light reaches our eyes and we see clouds as white. However, the rain clouds are gray instead of white, so what is the reason?

The reason for the gray color of the clouds

Rain clouds appear gray because of their thickness, when the cloud collects more water droplets and ice crystals, it becomes thicker and denser, and the thicker it gets, the less white light is able to penetrate it, and thus the light scattering increases, so that not much light passes to the particles on the side The lower base of a raincloud, reaching our eyes, is why the lower base of a raincloud appears gray when viewed from the ground.

This effect becomes more pronounced as the water droplets get larger, before they are large enough to fall from the sky as rain or snow.

Also read: Linear clouds..what are they..and why do they appear in the sky?

Also read: Why does earthworm come out to the surface of the soil after it rains?