Cary Martynuik, a moon researcher with a part in movie, "Moon Rising", asks good questions about the Moon's appearance as seen from Earth. Martynuik contends our atmosphere and its light diffusion and scattering properties, only makes the moon appear colorless. Our eyes simply do not receive the color information before it's deflected? Is there color info not reaching the earth's surface? It's a good question! Here's a link to an eight minute video, "Why the Moon Appears Grey From Earth".