Snow is like a mirror, it reflects the colors around it. Direct light on snow is very warm with a peach or golden tone, shadows are cool, full of blues and purples. When it comes to painting snow there really isn't any pure white.
It might be surprising to see just how colorful the snow palette really is... take a look at these two paintings.
I've made a swatch pallet of the colors that these paintings share.
Would you have ever guessed that a snow scene and a beach scene share so many of the same hues? The winter palette is amazingly colorful!