Answer:
Most all of the visible light striking the snow or ice surface is reflected back without any particular preference for a single color. Most natural materials absorb some sunlight, which gives them their color. Clean snow, however, reflects most of the sunlight, creating a white appearance.
[ I commented on the other answer with the same little add-on, then I realised I could add an answer. Even though this is four days ago, meaning the person who asked the question doesn't need another answer, I hope to give someone else who might be looking at this some insight. ]