Several teachers and students have asked what the planets look like in "true" or "natural" colors. They've noticed that each planet's appearance can vary greatly in photographs, and that many of the photographs are labeled as a "false-color" view. Many times scientists enhance the colors, or contrast of an image to draw out more detail. It's actually quite difficult to reproduce in a photograph the way we see things with our eyes. It's especially difficult to do with the special, sensitive "black & white" (gray-scale) cameras on most telescopes, satellites, and space probes.
The challenge for teachers is increased by the abundance of images now available on the Internet. Since I was unable to find a good web page to send teachers to, I've created this one. The photos below are the best I could find as representatives of what the planet would look like if we were looking out the window of a space craft as it passed by the planet.
The Hubble Space Telescope web site has a nice tutorial on the Meaning of Color in Hubble images. The information there provides a good explanation for color in most of these cameras.
The Planets as seen in natural or true colors
(click images for larger images; these photos do NOT show the comparative sizes)