> to reveal color selection as being logical, predictable, and driven by principles anyone can learn.

In that regard, is there any sort of algebra for color compatibility to quantify legibility?

Specifically, say we have some text and change the background and font colors from default values.

When I do this, I generally have no sense for the color change’s impact on readability or if the contrast would hurt my eyes until I take a look at the output. Then when I make a slight change - has it gotten better or worse? It feels so murky.

I know there are more factors at play: font choice, font size, brightness of screen, etc. but does anyone know of a rough heuristic for or programmatic means of checking?