Long before any rover landed on Mars, the two Viking missions sailed there. Each had an orbiter and a lander. Viking I returned the first surface image of Mars on July 20, 1976, and both soon sent back many more, including the one above from Viking II. Reading the caption written for this picture at the time, it's clear NASA scientists labored to communicate that these weren't black and white pictures or filtered. They were actual images of Mars:
Scientists believe the colors of the Martian surface and sky in this photo represent their true colors. Fine particles of red dust have settled on spacecraft surfaces. The salmon color of the sky is caused by dust particles suspended in the atmosphere. Color calibration charts for the cameras are mounted at three locations on the spacecraft. Note the blue star field and red stripes of the flag.
And in the final line of the caption, they also make it clear the spacecraft is waving:
The circular structure at top is the high-gain antenna, pointed toward Earth.
Below, recent Pictures of the Day: