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Although it is often described as “snow white,” snow does not appear white under all conditions. Sand, soot, rust, bacteria and algae in the air or on the ground can change the color of the snow. The natural phenomenon known as “watermelon snow” or “pink snow” is caused by the algae called Chlamydomonas nivalis, which lives in cold environments. The red pigment produced by this alga causes the snow to turn pink or reddish, especially in high altitude and snowy areas.
In Antarctica, penguin droppings can make snow appear pinkish, while the blue hues seen on glaciers are created when dense ice absorbs red and yellow wavelengths and reflects blue light.
