Protesilaos Stavrou has uploaded two (light and dark) “accessibility” themes with “consistent minimum contrast ratio between background and foreground values of 7:1 or higher" to Melpa. See https://www.youtube.com/watch?v=zofd0O12XWE <https://www.youtube.com/watch?v=zofd0O12XWE>. The source code is on GitLab at https://gitlab.com/protesilaos/modus-themes <https://gitlab.com/protesilaos/modus-themes>.