Segregation of basic colors in an information display.

Previous studies of the role of color in visual search have shown efficient coding for as many as six colors in a high-density display. In an effort to increase this limit, we established an optimal basic color code from extensive surface-color-naming data. This code yielded excellent segregation in a visual search task: The time required to find a critical target of a cued color increased only marginally as up to nine groups of different colors were added to the display. It made no difference whether the cue was provided by name or by example. Significant color differences in this task triggered a second experiment, which examined the detectability of the critical target feature in the periphery. A close correlation was found to exist in the order of color performance between the two experiments. Color segregation was tested again in a third experiment, in which subjects were required to count the number of targets of the cued color. The colors again segregated well. A final experiment tested the proposition that it was the basic nature of the colors that was responsible for the good segregation. When seven basic colors were pitted against seven equally discriminable nonbasic ones in a modified version of the visual search task, no significant difference was found between the two groups. It is concluded that basic colors segregate well not because they are universally named but because they are well separated in color space.