No color deficiency
Protanomaly or Protanopia
Deuteranomaly or Deuteranopia
Tritanomaly or Tritanopia
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• Most common types
• “Red-green color blindness”
• Most often caused by mutations on X chromosome
Why should you make your graphics colorblind friendly?
  • Colorblindness is common, especially for people of Northern European ancestry
  • Affects up to 8% of men and 0.5% of women
  • If your manuscript is sent to 3 male reviewers of Northern European descent, there’s a >20% chance that one of them will be color blind

    Sources: Deeb 2005 Clinical Genetics; Katsnelson 2021 Nature
How do your graphics appear to people with different types of color blindness?

Color blindness simulators & tools for selecting accessible color schemes:

https://colororacle.org/

https://projects.susielu.com/viz-palette

R package to simulate colorblindness on R figures: https://github.com/clauswilke/colorblindr

Adobe Illustrator: View > Proof Setup > Color Blindness

Example of colorblind-friendly palette
created by colorblind scientists Masataka Okabe & Kei Ito
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Colorblind-friendly palette

Figure from https://jfly.uni-koeln.de/color/ by Okabe & Ito
For users of R http://www.cookbook-r.com/Graphs/Colors_(ggplot2)/: cbbPalette <- c(“#000000”, “#E69F00”, “#56B4E9”, “#009E73”, “#F0E442”, “#0072B2”, “#D55E00”, “#CC79A7”)

Colors: friend or foe? – Choosing color schemes
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https://learnui.design/tools/data-color-picker.html#palette
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http://colorbrewer2.org/#type=diverging&scheme=BrBG&n=5
Other suggestions
  • Use contrasts not only in hue, but also in brightness
  • Use shape as well as color to convey differences
  • Make graphics grayscale-friendly. Even people with normal color vision may print in black and white!

    Suggestions from https://jfly.uni-koeln.de/color/ by Okabe & Ito

Also avoid red-green contrasts in stained images

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No color deficiency
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Protanopia
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Deuteranopia
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Tritanopia

Better to convert red to magenta, which can be distinguished from green

Figure from https://jfly.uni-koeln.de/color/ by Okabe & Ito