I noticed that in dark mode hyperlinks are hard to read.
The author pointed me to the CSS style sheets folder:
control-click (or right-click) on the app in the Finder and choose ‘Show Package Contents’, then go in Resources/webview.
There you will find the styles.css file.
In there, add this block:
body.dark span.a {
color: cyan;
}
with the color of your liking, obviously.
Restart, the app, and voilà, fixed! 