Quote Originally Posted by arthurking83 View Post
I've never found WB as a reason to differentiate white and or grey, or even black.
In fact I regularly use black as my whitebalance reference point.
Arthur, this topic is routinely discussed on international fora where snow is a commonplace.

Some cameras require a neutral grey card to take a custom white balance. Some are happy to use a small sheet of white paper. Undoubtedly there are some that have other requirements.

Significant amounts of snow in a shot affects the WB because snow is not actually white, but cameras tend to assume that it is.