Scientists have devised a different type of color scale for scientific maps that makes them more readable for the color-blind.
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.”
Ditching this multicolored scale may even save lives. Harvard University researchers found that when traditional rainbow-colored 3-D computer models of arteries were replaced by 2-D models using a red-to-black color scale (pdf), doctors’ accuracy in diagnosing heart disease jumped from 39 percent to 91 percent.
For planetary scientists, changing from the rainbow scale will be difficult. Topography maps especially have for almost a century have shown low regions as blue with high regions as red. This is what scientists, and even ordinary people, have come to expect.
Still, to make these maps understandable to the colorblind seems smart. I wonder if the idea will catch on.
Hat tip from reader Milt Hays Jr.