I’ve always heard that some people have trouble with text flow with sans-serif fonts, but are there problems with serif fonts as well? I know some fonts are - if not uncomfortable, just weird to read a lot of text in. I always was told “if it comes down to one font, choose serif.” “Book-ish” fonts are preferred, and many fonts are great for headers or headlines or decorative text, but suck to read blocks of body text in. There are also preferred fonts for people with dyslexia.
(There it in the first example - serif fonts can trip up people with dyslexia, so in their case you don’t want the letters to flow together for speed.)
I remember being surprised what colors don’t work together for people with color blindness. If you need a link to stand out from the rest of the text, it often works better to make links a contrast/brightness change rather than a color change for people with reduced color sensitivity.