Mercury in color from Mariner 10: Flyby 1 departure view
This mosaic of Mercury was assembled by Ted Stryk from many individual frames taken by Mariner 10 as it departed Mercury after its first flyby on March 29, 1974. The Caloris basin is just visible on the terminator (day-night boundary) on the left side of the image.
Stryk composed this false-color view by using ultraviolet frames in the blue channel, blue frames in the green channel, and "minus UV" in the red channel. This image represents the best global view of Mercury before MESSENGER.