Review Of Colour Terms And Simultaneous Contrast Research For Cartography

Abstract

Colours that are next to a map colour change its appearance by simultaneous contrast (the term induction is also used to describe the effect). The problem of simultaneous contrast on maps has been described repeatedly in the general literature on colour use in cartography and has been recognized as a confounding variable in cartographic research on colour. This review article clarifies important distinctions between lightness constancy and brightness contrast effects that interfere with the interpretation of the results of previous research. Likewise, induced changes in hue are often described as shifts toward the complement of the surrounding colour but many different definitions of complementarity exist, and these distinctions are described. Review of the induction literature from other disciplines reveals conflicting conclusions based on varied stimulus configurations that do not approximate the complexity of a map. To establish a perceptual structure relevant to the map reading context, induction must be judged under realistic illumination conditions and test colours must be embedded in a matrix of other colours that includes reference whites. Review of past attempts to explain induced changes in colour reveals that the opponent process approach is the most common and promising avenue for modelling induction.