Nothing prevents us from taking color pictures. In fact the cameras on the MER rovers are superb, the best we've ever sent to Mars. There's been a steady improvement over the years, starting with the simple rotating-mirror and photocell cameras on the Viking Landers, to the not-too-shabby Pathfinder IMP, to the exquisite MER PanCams.

This little tempest-in-a-teapot is just about the pictures that NASA releases to the public through its Public Information Office. It shouldn't affect the images that the scientists are using internally; I sure hope not, for the sake of science!

We also need to keep in mind that the geologists aren't actually all that interested in pretty color pictures. For their purposes, they treat the rover PanCams like imaging spectrometers: Each pixel of an image represents up to six measurements of light at specific wavelengths. That's per-camera: Six visible filters on the left camera, one UV filter and five infrared filters on the right camera, for a total of 12 wavelengths. Very likely the geologists just examine monochrome images looking for telltale highlights and other spectral signatures.

Basically, all's right with the world. This is just a little speedbump on the road to the public's understanding of Mars.