Color blindness is surprisingly more common than many of us realize - even the people who experience it. My elderly mom was coloring pictures in weird psychedelic combinations that I thought was just a unique choice until I realized she also was using everyone else’s towels and toothbrushes by accident. She has trouble distinguishing shades of red such as dark purple vs gray and brown.
This thread has some useful resources and it’s handy to screenshot your text and run it through these simulations to see how distinguishable your links are when seen through different variations of color-blindness: