Clouds appear in various colors depending on several factors, primarily the type of light hitting them and their composition. During the day, clouds typically appear white because water droplets and ice crystals scatter all wavelengths of light equally (unlike air molecules).
Different cloud colors occur due to:
- White: Complete scattering of all visible light wavelengths
- Gray/Black: Thickness of clouds blocking sunlight
- Pink/Red: Sunrise/sunset light reflecting off cloud bottoms
- Green: Usually seen in severe storm clouds due to water density and light scattering
The appearance can also be affected by pollution, dust, and other atmospheric particles that influence how light interacts with the cloud droplets.