Avoid colour combinations that are especially hard for colour-blind people to see.
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
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.
Some mildly colour-blind people are able to see a colour, but only if there’s a sufficient “mass” of it. Use larger areas and thicker lines if possible.