Choosing the correct colours
Avoid colour combinations that are especially hard for colour-blind people to see.
Example of colour combinations that should not be used
Using shades of a single colour
Use various shades of a single colour, instead of multiple colours, to help avoid colour blindness issues. This can be done by varying the luminance or saturation and holding the hue constant.
Example of how to use shades of one colour with varying luminance or saturation
Colour-blind people can still perceive contrast, as well as differences in hue, saturation and brightness. Use bright colours which are easier to distinguish rather than dim ones, which tend to blur into one another.
Use larger areas and thicker lines
Some mildly colour-blind people are able to see a colour, but only if there is a sufficient “mass” of it. Use larger areas and thicker lines if possible.