True color images such as this famous view from Mars Pathfinder are useful for displaying scenes exactly as the human eye would observe them. Values in Red, Green, and Blue are recorded for each pixel and composited to form a final, color image.
	A "false color" image, on the other hand, is a greyscale image that has been filtered to display an arbitrary range of colors. Such images can be useful in observing specific qualities in the subject matter, such as would vary by optical density.