I am going to discuss the making of this piece a little more. Yesterday I showed a series of photos of the creation of the piece. I want to dig a little deeper into my method tonight. Below is how the piece looked as I began to lay in the snow.
Here is a close up of the lower left part of the painting. Above you can see I started by painting white tinged with cobalt over the passage. Next I made a pile of white tinged with cadmium yellow on my palette. I then used that to model the snow. I am painting the white tinged with cadmium yellow down into the cobalt violet and white already wet on the passage. Where it received the most light it got the cadmium yellow, as the forms curved away from the light it remained cobalt violet. Where it went into shadow or a furrow in the snow I hit it with a cobalt blue and white shadow note.
I then accented the few planes that turned towards the raking light enough to catch the full sun with a thick stroke of the cadmium yellow and white mixture. The ruts were actually the footsteps of the group of painters I worked with that day, stomping around and scoping out the various places to set up in the barnyard.
So I built up my snow using an orderly system of putting one color down and throwing a compliment into it in increasing amounts as it turns into, and then is hit by the light. I like to do this with cobalt violet and cad. yellow. But you could do it with many pairs of colors, such as ultramarine and burnt sienna or viridian and cad. orange. I am exploiting the fact that the shadows are the compliment of the light. I am also dropping the value of the halftone parts of the light enough that I can model within them. Had I kept them very light, the sunstruck portions would not have been enough brighter to show up. Keying snow down slightly makes it far easier to model, or show its forms. Just white paint won't cut it.