A different type of color scale for maps that the color-blind can read
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.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon. from any other book seller, or direct from my ebook publisher, ebookit.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
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.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon. from any other book seller, or direct from my ebook publisher, ebookit. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
About bloody time! I cannot figure out the colours on any of these maps.
Side note: To understand what a colour blind person sees, consider these three videos where the PIP box shows the real image, and the main screen shows the Colour blind filtered view.
Protanopia:
https://www.youtube.com/watch?v=KcB_NhUNP0I&t=33s
Deuteranopia:
https://www.youtube.com/watch?v=-UNQxXfY2AI
Tritanopia:
https://www.youtube.com/watch?v=ZW2NVBvI9TA&t=28s
My family says I see everything very green. Whatever.
This is what scientists, and even ordinary people, have come to expect.
I suspect that anyone who grew up in the 80’s and younger will have no problem adapting to different visualizations. The same is probably true for many older people. We are just so accustomed to graphical representations that it is easy to go from one method to another.