That's no Instagram filter lending a nostalgic sepia tint to the image above.
The reddish haze pervading the photo of NASA's Curiosity rover comes from a protective dust cover shielding the lens of the rover's Mars Hand Lens Imager (MAHLI), which took the picture September 7.
So named because it is meant to fill the role of the handheld magnifying glass for a human geologist, MAHLI is equipped with two light sources—one producing white light and the other radiating ultraviolet light—for illuminating geologic specimens. The imager is mounted on the end of Curiosity's robotic arm, which allowed it to turn and snap a portrait-style shot of the cameras and other instruments mounted in the "head" at the top of the rover's more than two-meter-high vertical mast.
At the same time, the cameras atop the mast were inspecting MAHLI, its dust cover and other instruments on the 2.1-meter-long robotic arm. Having received a clean bill of health, MAHLI opened its cover the following day and began imaging the rover's environs with newfound clarity.