You might enjoy articles from BetterExplained. For example: https://betterexplained.com/articles/q-why-is-e-special-2-71...
There might be an article about this specific technique.
Thanks for the pointer -- I have an article here.
https://betterexplained.com/articles/colorized-math-equation...
If you hover any diagram, there are options for a colorblind-friendly version.
If it's for broad consumption, it's best to consider people with poor colour vision.
The usage of text color on this image caption is brilliant. It never occurred to me that you can do this technique to explain a diagram. Definitely love it. Will steal this technique for my own purpose.