My winter scene as noted in my recent blog "Many Shades of Grey" has earned itself a warm and contrary color watercolor underpainting.
I chose this color for two reasons. First, as orange is the complementary color of blue, and the shady snow areas will be blue, I felt that such a wash of orange will help the snow stand out in the painting.
My second reason for choosing an orange underpainting deals with the warmth of the scene, especially in the background treeline, where soft orange can be seen in the reference photo (see my earlier blog for that photo).
So I encourage you to experiment with a contrary color underpainting.