This image of Mars was constructed from three different black-and-white images recording red light, green light and blue light reflected from the planet. These filters and the colors assigned to them were chosen to correlate to Mars’ actual colors. Not surprisingly, the brightest black-and-white image of the red planet is the one taken through a red filter, because Mars has a strong red coloring in visible light. However, note that the northern ice cap in these black-and-white images is equally bright in red, green and blue light because its actual color is white. When red, green and blue light combine in equal measure, they produce white light, a reverse prism or rainbow effect.
