Clouds are masses of tiny water droplets and ice crystals that float in air. As such they don not have any colour but some look white and some grey but rain clouds are black in colour due to many reasons but all of them are not black they are sometime grey depending up on the appearance of clouds.
Rain Clouds black in colour and change shape:?
Some changes shape continuously as parts of the cloud evaporate when they come in to contact with warmer air and clouds are white and black at the same time as the thickness increases colour of clouds changes and rain bearing clouds will be black.
Why are Rain Clouds Black in Colour and Dark
Classification of Clouds by Appearance:
Clouds are classified mainly by their appearance dimension, shape, structure and texture. While stratus clouds are sheet-like, fair weather cumulus clouds consist of piled up masses of dazzling white clouds. They are made of water droplets.
Cirrus clouds are curly white made of ice crystals at higher altitudes. In these clouds, water droplets or ice crystals are loosely packed and so light can pass through them without much loss in intensity.
Stratocumulus Clouds: Some of the clouds which cause rain are the stratus and stratocumulus clouds which are near-earth clouds. Stratocumulus clouds are not as thick as stratus clouds and so they have light and dark areas.
Altostratus clouds form smooth white or grey sheets across the sky. Sometimes these clouds are no thick that the sun or the moon cannot be seen through it. At times the difference in thickness may cause relatively light patches between dark parts but the surface of the clouds do not show any relief.
Nimbostratus clouds are low, amorphous and occur at higher altitudes. These are dark, grey and uniform. Cumulonimbus are the main rain clouds which are black. This is because light cannot penetrate through them as they are deep and densely packed with water droplets, ice and snow particles.
If we look from an air craft flying at high altitudes, these clouds will load dazzlingly white instead of rain cloud black in colour, as they reflect all the light falling on them. But for an observer on the ground the clouds may look black and be raining. Clouds are thus white and black at the same time.
As the thickness increases colour of clouds changes and rain bearing clouds will be black.
Noctilucent clouds also called as night shining clouds, are tenuous cloud-like phenomena in the upper atmosphere of Earth and consists of ice crystals and visible during astronomical twilight.