True and False... Color

Now here's something that you don't normally think of: Are the images you're seeing actually the color that you would see them? If you're talking about stuff on earth you can be pretty sure that more often than not it is. However when you're dealing with images from Hubble or the Mars rovers you run into other things all together. That's where "True" and "False" colors come in.

As it turns out because of the process used to record these images. The pictures that we see aren't necessarily in the colors our eyes would perceive. They don't take the picture all colors at once. They take a series of pictures through different color filters (some in the infrared and some in the ultraviolet even) and then attribute the most useful colors to those different grey scale slides in ways that make what you're seeing most effective.

As it turns out the Hubble telescope, since it uses such a broad range of spectra and since it is often dealing with things that are outside the visible light range uses color combinations that are "False" colors. While the Mars rovers are actually trying to use calibration systems which turn out very close approximations of what the average human eye would receive.

Full article at: True or False (Color): The Art of Extraterrestrial Photography