I’ve created 2 themes on https://color.firefox.com/ ~ one light themed & one dark themed. Would it be possible to configure these as a dynamic theme which follows my system’s light/dark settings? (I’m using Fedora if that’s relevant)
I don’t think Firefox Color can do that. At best you could test and set colors using Color, and then export the settings for both as a theme .zip or .xpi files, and then combine the two to a single manifest.json file. Inside the manifest, a "theme"
key would be color properties for “normal” theme and "dark_theme"
would be for dark-theme. After that you would submit the theme package to get it signed after which it can be installed as a real theme.