The previously rather drab little Martian moon of Deimos can now be seen in a new light, thanks to the latest pictures shot by the High Resolution Imaging Science Experiment, or HiRISE, on board NASA's Mars Reconnaissance Orbiter. Captured on February 21st, 2009, using near-infrared, and red and blue-green filters, the new images show subtle colour variations on the surface. These are probably caused by the exposure of surface materials to the space environment, which leads to darkening and reddening. Brighter and less-red surface materials have seen less exposure to space due to recent impacts or downslope movement of regolith.
The pictures can be seen here.