NASA / JPL / Cornell / composite by Errol Coder
click image to enlarge
Here is another false color image using Opportunities PanCam using the L2, L5, and L7 filters. In this one you can see a bit more lighter reddish streaks in respect to the darker under soil. You can also see the darker "ditch" going from the top left to the bottom right of the shot. This is a great example of parts of Mars where the darker lower soil is revealed creating almost a "stream bed" looking area. This is sometimes caused by soil drifts removing the lighter top soil of the side of the crevice revealing the under soil.