Abstract
Procedures exist for evaluating colour in terms of a scientific specification which can be developed to quantify the visual impact of colour differences. In this paper the essential theory of colorimetry is outlined and discussed from a cartographic standpoint and one method of measuring a colour specification is described. The practical results are used to illustrate the ways in which colorimetry might help the cartographer and it is concluded that given further research the scientific measurement of colour could offer an objective basis for the analysis and use of colour in map design.