CSTE Spatial Analysis Workgroup

End of the Rainbow? New Map Scale is More Readable by People Who Are Color Blind

End of the Rainbow? New Map Scale is More Readable by People Who Are Color Blind


The improved palette also avoids some of the problems existing data visualization schemes pose for people with typical vision

Betsy Mason

August 9, 2018

Data visualizations using rainbow color scales are ubiquitous in many fields of science, depicting everything from ocean temperatures to brain activity to Martian topography. But cartographers have been arguing for decades the “Roy G. Biv” scale makes maps and other figures difficult to interpret, sometimes to the point of being misleading. And for the those with color blindness, they are completely unintelligible.

Now scientists at a U.S. Department of Energy laboratory have developed a color scale that is mathematically optimized to be accurate for both color blind people and those with normal vision. The scale was described Wednesday in a new study in PLOS ONE. “People like to use rainbow because it catches the eye,” says lead author Jamie Nuñez, a chemical and biological data analyst at the Pacific Northwest National Laboratory (PNNL). “But once the eye actually gets there and people are trying to figure out what’s actually going on inside of the image, that’s kind of where it falls apart.”