No color deficiency
Protanomaly or Protanopia
Deuteranomaly or Deuteranopia
Tritanomaly or Tritanopia
• 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:

R package to simulate colorblindness on R figures:

Adobe Illustrator: View > Proof Setup > Color Blindness

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

Figure from by Okabe & Ito
For users of R cbbPalette <- c(“#000000”, “#E69F00”, “#56B4E9”, “#009E73”, “#F0E442”, “#0072B2”, “#D55E00”, “#CC79A7”)

Colors: friend or foe? – Choosing color schemes
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 by Okabe & Ito

Also avoid red-green contrasts in stained images

No color deficiency

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

Figure from by Okabe & Ito