Some about pages (like about:home) support dark theme. Maybe it's something we should do as well in about:debugging
Matt, could you check if dark theme support is something they want to push forward for all about:pages? Based on this information, we should discuss with Harald to see if we make it MVP or not.
Matt shared an about this during the standup. It is not entirely clear how this will be applied to all about:pages at the moment, so let's move it to m3+