What weather does the sky show in different colors?

The color of clouds can also indicate some kind of weather. For example, the color of hail cloud is first white and then black, and then red appears in the cloud, forming a white, black and red distorted cloud with khaki edges. Black is caused by the sun's inability to penetrate clouds; White is the result of non-selective scattering or reflection of sunlight by clouds; Red and yellow are the phenomena that some cloud droplets (ranging from one thousandth to one hundredth of a millimeter in diameter) in the cloud selectively scatter sunlight. Sometimes rain clouds are pale yellow, but the color of the clouds is uniform and will not stir. There are also many proverbs that predict hail from the color and shape of clouds. For example, there is a proverb in Inner Mongolia, such as "I am not afraid of the darkness in the clouds, but I am afraid of the dark red in the clouds, and I am most afraid of the white worms in Huang Yun". In Shaanxi, there is "Huang Yun turned over and hail; Stir clouds and hail in groups; There are proverbs such as "When clouds fight, it will hail" and "The dark clouds in Huang Yun are red, the clouds toss and turn, and there are many hail disasters". There are also some sayings, such as "the dark clouds roll into a ball in the afternoon, and the wind, rain and hail come together", "The sky is yellow and sultry, and the Tianhe water growls to prevent ice eggs", all of which show that when the air convection is strong, the clouds develop rapidly, like smoke, and the clouds roll up and down, which is easy to hail.