Don Davis is a space artist and animator. He is a member and Fellow of the International Association of Astronomical Artists. Visit his website to see his paintings and his writing on the colors of Mars.
In 1971 I was being trained to work with the airbrush by the map artists at the U.S. Geological Survey's Branch of Astrogeologic Studies in Flagstaff. However, the project I ended up spending about a quarter of a man-year on was a hand-painted map globe of Mars.
Opportunity celebrated reaching 5000 sols by taking a self-portrait with its Microscopic Imager. The self-portrait was extended a week later with an additional lower tier covering the wheels on the ground. This photo has been artificially colorized using a realistic Mars palette.
On sol 5000 of its 90-day mission, Opportunity used its Microscopic Imager (MI) to capture a view of itself on Mars. The MI is designed to view targets very close to the lens and has no focus capability, so its images of the rover are out of focus. It took 17 MI frames to cover the rover. This mosaic has been artificially colorized using a Mars-appropriate color palette.