Visual search with color.

Three experiments were conducted to discover how rapidly people can find a particular target when they know the color of the target. The subjects searched for specific-colored three-digit numbers among other three-digit numbers on a circular display screen. Three factors had profound effects on search speed. Search time increased dramatically (and approximately linearly) as the number of display items of the target's color increased from one to all of the items on the display. Search time also increased with the number of items not of the target's color (background items), if the color of those background items was sufficiently similar to that of the target. If the color of those background items was dissimilar to that of the target, then the background items had no effect. An effect of patterned versus random placement of target-colored items was also demonstrated.