Toro Crater may have experienced hydrothermal alteration, producing diverse minerals. The mineral diversity leads to diverse color in HiRISE, especially when enhanced as in this subimage .
In general the blue and green colors indicate unaltered minerals like pyroxene and olivine, whereas the warmer colors indicate alteration into clays and other minerals. The linear north-south trending features are windblown dunes that are much younger than the bedrock.
Written by: Alfred McEwen (1 February 2012)
This is a stereo pair with ESP_025344_1970 .
More info and image formats at http://hirise.lpl.arizona.edu/ESP_025067_1970
Image: NASA/JPL/University of Arizona