The filters used in the image in post 1 were L2L5L5L7. Only L5 is in the human visible light spectrum. I am not looking at the color, only the characteristics of the surface material.

This is the same image in L5 only. My analysis still stands, coloration is not the issue. More answers to follow.

http://marsrovers.jpl.nasa.gov/galle...GP2417L5M1.JPG

dfrank