Why is are clouds white?
Cloud
These cumuliform clouds of free convection have clear-cut medium-grey flat bases and white domed tops in the form of small sproutings and generally do not produce precipitation.[52] They usually form in the low level of the troposphere except during conditions of very low relative humidity when the clouds bases can rise into the middle altitude range. Moderate cumulus is officially classified as low-level and more informally characterized as having vertical extent that can involve more than one altitude level.[26]