USWDS have a cool palette system where color pairs from their palette have predictable WCAG color contrast (unlike in e.g. Tailwind's default palette), but I rarely hear of projects using USWDS colors:
https://designsystem.digital.gov/design-tokens/color/overvie...
> We call the difference in grade between any two colors the magic number. Magic numbers have the following contrast implications:
> A magic number of 40+ results in WCAG 2.0 AA Large Text contrast (example: gray-90 and indigo-warm-50v).