[selfsimilar]

WCAG doesn't define a maximum contrast.

edit:

Interesting discussion about the effect of fonts, dyslexia, and dark-mode wrt "too much contrast" in this UX StackExchange thread. https://ux.stackexchange.com/questions/123504/maximum-contra...

[cratermoon]

Yes, I know. The question was about what is "dark enough", given a light foreground text. #444444 is dark enough.