Question: Are clouds actually white or is it just an illusion?

Freya Addison answered on 18 Nov 2019:

What a fantastic question. The Sun emits the full visual spectrum of light which is white to us; it only becomes a rainbow if we split up the light. The water droplets in a cloud scatter each of the colours of light pretty equally, therefore, they appear white. However clouds can appear grey too, and this is because less light is getting through; bigger droplets will scatter light more so less light gets through to the bottom of typically rain clouds so they appear darker.