Found this on slashdot.com:

Colorization of Mars Images?
Posted by michael on Friday January 09, @02:15PM
from the technicolor dept.
ares2003 writes "There is no scientific reason, why JPL is colorizing Mars in that dull red tint as in their press release images. In the latest panorama image, there is a hint, that they deliberately altered the colors, as the blue and green spots on the color calibration target (the sundial) suddenly converted to bright red and brown. Source of original images: 1, 2 - (for highres replace "br" with "med"). At normal weather conditions, as we have at the moment, there should be a blue sky on Mars and earthlike colors. Furthermore the sky looks overcasted on the pictures as it cannot be considering the sharp shadows on the sundial. If the sky was overcast, then because of diffuse lighting, there would be no shadows. A few years ago, I did an investigation about that very same topic for the Viking and Pathfinder missions."
http://science.slashdot.org/article.pl?sid=04/01/09/1724246&tid=

As you can see in this image there are blue and green tabs on the sundial calibration target:

Yet in this released panoramic image, the blue and green has inexplicably changed to brown and red:

Perhaps someone could post an image of this panorama with the blue and green tabs given back their normal colors.

Bob Clark