Trends and Issues in the Use of Quantitative Color Schemes in Refereed Journals

This article reports on color usage in quantitative thematic mapping, drawing from an evaluation of maps published in eight geographical journals over the ten-year period from 2004 to 2013. During this period we found that color has become the preferred method to represent quantitative data sets, with the percentage of quantitative color maps relative to all quantitative maps rising from 18.4 percent in 2004 to 69.9 percent in 2013. We reviewed a sample of 440 maps from this period to assess the nature and appropriateness of their respective color schemes. We found the following frequencies of color scheme usage: spectral (30 percent), sequential (25.9 percent), diverging (25.7 percent), traffic (7.7 percent), and uncategorized (10.7 percent). Each scheme exhibited a distinct set of significant associations with particular map and data attributes, including subject matter, symbolization method, data polarity, and map size. Diverging and sequential schemes were the most effective, having strong association...