My add-on displays an options page on the
about:addons menu, but I’m having some trouble getting it to work well when the user is running the dark mode theme on Firefox 89.
All of the UI on the
about:addons page is in light more or dark mode.
I’ve already tried
window.matchMedia('(prefers-color-scheme: dark)').matches and that returns
false, so it looks like either Firefox is not using that media query when the theme is set to dark or it’s not giving add-on the ability to see that media query.