I really like the polished look of GNOME and its default theme Adwaita, but there is one thing that has been bugging me for some time. By default server side window decorations are light and if an app has a dark UI and uses a server side window decorations, you get a dark window with a light title bar. It doesn’t look every nice and when you maximize the window, it’ll get even worse because you get a nice black-and-white hamburger (black top bar, light title bar, and dark window content).
There are quite a few apps suffering from this: Atom, Firefox Developer Edition, Blender,…
But Mutter actually allows the clients to set a theme for their window decorations even though they’re rendered on the server side. They just need to set an x window property GTK_THEME_VARIANT=dark.
And I think the difference speaks for itself:
You can test it by executing: xprop -f _GTK_THEME_VARIANT 8u -set _GTK_THEME_VARIANT dark
and clicking the window where it should apply.
Are you a user of one of the apps that would benefit from it? Or even a contributor? Try to convince the project to implement this tiny change. If you’re a distro maintainer of such an app, you may consider applying a small patch.