What causes colored snow?
Did you know that snow is not always white? Red, blue, yellow and even black snow is sometimes seen in many parts of the world.
The snow is not really these colors! If you live in a dusty place, bits of yellow dust in the air may stick to the falling snowflakes and make them look yellow. In other dusty places, the snow can be brown, or even black.
If you built a snowman in the cold Arctic, he might not be white. He might be red, green, or blue. The bright colors come from many tiny plants that change the color of snow after it has fallen. “Snow” is the name for the tiny ice crystals that form when water vapor in clouds freezes.
Sow is usually white. This is because the tiny crystal surfaces of fresh snow reflect the white light of the sun and make the snow appear white. When snow melts, it becomes colorless water.–Dick Rogers