Answer
Snow would appear to be yellow-orange.
Work Step by Step
The blue end of the visible spectrum is scattered most by oxygen and nitrogen molecules in the atmosphere. This occurs all along the path of sunlight. If the atmosphere were several times denser, even more high-frequency light would be scattered sideways, and by the time the sunlight hit the ground, mostly low-frequency components of light would remain (namely red, orange, and yellow). At sunrise or sunset, the sun, and the snow, would appear to be deep red.
This is discussed on pages 512-513, and shown in Figure 27.18. Check point 2 on page 514 is also relevant.
