Good to keep in mind - I’m guilty of getting a bit carried away with dense colour maps myself!
Colour me better: fixing figures for colour blindness
Images can be made more accessible by choosing hues, shapes and textures carefully.
Red–green colour blindness is the most common form of colour vision deficiency; blue–yellow colour blindness is less common, and achromatopsia, the inability to see most colours, is rarer still. In northern Europe, 1 in 12 men and 1 in 200 women have a colour vision deficiency — enough people that making your work accessible is simply the right thing to do, says Harden. “I consider using colour-blind-friendly palettes and colour maps as a way to express empathy to people who are truly interested in your work.”
But to put those numbers in more pragmatic terms, if all three of a paper’s reviewers are male and of northern European descent, there’s a one in five chance that one of them will have a colour deficiency.