I think there's a very easy solution to this problem: use a dark theme for this wiki, instead of a light one. Using Fandom's blackish color instead of white would make links, y'know, readable. Both green and cyan would look good on buttons and the wiki's navigation; whichever one remains could replace the current background color. Of course, the wordmark would need to be tweaked as well:
This one's easy, too: just make the words "open" and "source" white!