Mars Rover only has black and white camera... Sure it's on mars?

[Cebu_4_2]

Shadow Portrait of NASA Rover Opportunity on Martian Slope

NASA's Mars Exploration Rover Opportunity caught its own silhouette in this late-afternoon image taken by the rover's rear hazard avoidance camera. This camera is mounted low on the rover and has a wide-angle lens.
The image was taken looking eastward shortly before sunset on the 3,609th Martian day, or sol, of Opportunity's work on Mars (March 20, 2014). The rover's shadow falls across a slope called the McClure-Beverlin Escarpment on the western rim of Endeavour Crater, where Opportunity is investigating rock layers for evidence about ancient environments. The scene includes a glimpse into the distance across the 14-mile-wide (22-kilometer-wide) crater.
Image Credit: NASA/JPL-Caltech

http://www.nasa.gov/sites/default/files/styles/946xvariable_height/public/pia17956.jpg?itok=jOLEw_p4

[vacuum]

Cameras
Each rover is equipped with a Pancam (short for Panoramic Camera), and each Pancam (contains two digital cameras. Set 30 cm (11.8") apart, the cameras function like left and right "eyes," so we're getting back breathtaking, 360-degree stereo color panoramas from each MER.
http://www.exploratorium.edu/mars/images/pancam.jpg
The Pancam
Image courtesy of NASA/JPL-Caltech
Each camera in the Pancam has a CCD (charged-coupled device) sensor with a 1024 x 1024 pixel array. That's a total of one megapixel—low resolution compared to today's consumer camera specs! These CCDs only detect the presence or absence of light; in other words, they're black-and-white cameras. To create those beautiful full-color images we've come to expect from our space missions, each camera has a wheel with eight positions for colored filters. By taking multiple pictures through different filters, scientists back on Earth will be able to construct color images.
There are a few specialized filters, too. The Pancam's "left eye" specializes mostly in visible colors, while its "right eye" specializes mostly in infrared wavelengths invisible to the naked eye. The left eye has a clear filter (without color), but both eyes have dark solar filters (for short-wavelength violet light on the left, and long-wavelength, near-infrared light on the right) for solar observations. These solar observations can be used to help determine the rover's position and orientation, as well as to image the sun.

[Dogman]

They use the spectrum of light and a spectroscope to determine what the emission lines to figure the real colors are and then add them in processing. Same with any deep space photo that has "color".


Part of the way they colorize the old black and white films and photos today. But way more sophisticated.