Color Coding of Information on Electronic Displays

Abstract

The effectiveness of human information processing depends largely on information coding. This paper reports an experiment on color codes suitable for use on electronic raster-scan displays (color TV-monitors). The experiment was designed to determine if results of color code experiments with surface and projected colors are also applicable to TV colors. The objectives were to select and optimize a multi-element color code suitable for TV displays that will permit each color to be correctly and reliably identified even when presented one at a time thereby requiring absolute judgements; and to determine the smallest TV symbol sizes which can be used with the color codes assuming that contrast ratio and luminance levels are within recommended ranges. For color symbols subtending a visual angle of 45′ or more and which were presented on the display screen one at a time 6 color regions could be found, that were judged correctly with a frequency of 90% or better. With symbols of less than 30′ of visual arc only 4 colors were reliably and correctly judged. It is possible that comparative judgement situations and training with the use of color codes could expand considerably the number of colors that could be used for coding purposes and also improve judgement reliability. Future research in this direction is recommended. Color regions from where coding colors should be selected, are shown by their representation in the CIE chromaticity plane. Some additional design recommendations for the use of color on raster-scan displays are provided.