Pictured is a snow camo pattern developed back in the 80's for the US Military, that was never adopted. Hard to see in the picture (poncho), but there are some very light colored shades also in the pattern. I also have a Goretex jacket that is reversible. Woodland camo on the outside, and this same Winter camo on the inside.
Anyone who has spent any length of time on the snow, can testify that it is hardly ever pure white. Only when the snow is fresh, and the sunlight, sky, and clouds can make it appear pure white, is short lived. Other factors like dust, dirt, tree pollen, etc. blown onto the snow, in addition to changes in terrain and shadowing, can make the snow multi shaded of whites, greys, and even some dark spots that are almost black.
The new Kryptek and MultiCam snow camo's are some good choices.
Some digital patterns like ACU and others actually work well in the snow when blending into natural terrain like timber and sagebrush because they more closely match the contrast.