Color in visual search.

Colored targets pop out of displays under conditions in which the standard red-green, yellow-blue and black-white mechanisms cannot directly mediate detection. Experimental evidence suggests that observers possess chromatic detection mechanisms tuned to intermediate hues such as orange as well as to hues characterizing the standard color-opponent mechanisms and that these mechanisms, as a group, form a fine-grained representation of hue within the central visual field. Spatially-parallel search is mediated by a single such mechanism that is spectrally sensitive to the target chromaticity but insensitive to the distractor chromaticities; different mechanisms are used to detect a single target in a way that depends on distractor chromaticities.