SUMMARY See https://github.com/NixOS/nixpkgs/issues/152914 We're using EasyEffects as example app. Note that the problem persist even with GTK_THEME=Breeze OBSERVED RESULT https://user-images.githubusercontent.com/6931743/147820677-6255a64e-0b61-4e2c-9260-0bd3136d6236.png EXPECTED RESULT https://user-images.githubusercontent.com/6931743/147840481-c62ff78d-4fad-4371-92c7-fda345ac3de2.png SOFTWARE/OS VERSIONS Windows: macOS: Linux/KDE Plasma: nixos-unstable/(available in About System) KDE Plasma Version: Plasma 5.21 KDE Frameworks Version: Qt Version: ADDITIONAL INFORMATION
Ok the plasma version is actually 5.23.3,while Qt is at 5.15.3
Also as additional data point if I run MOZ_WAYLAND_ENABLE=1 firefox firefox does not take the colors from the surrounding Breeze theme anymore,unlike again on X11 or even XWayland
Lutris additionally seems to not pick cursors and character but seems perfectly capable of picking the color scheme? https://user-images.githubusercontent.com/6931743/149671973-56ffa54d-d079-4e5e-9b56-90e2e6781ce9.png
> It is probably better to open a separate issue about GTK 3-based apps. I suspect that there is the same underlying problem: on wayland gtk{3,4} apps do not take the correct gtk setting from the theme > And for Firefox, do you perhaps set `GTK_USE_PORTAL=1`? With that enabled, the file chooser will be displayed by a different process, which might be running in a scope that does not include your session’s environment. Yes but I was not talking about the file chooser  So to recap: * Okular is how I want them to look, with a darker background * Lutris (GTK4) takes the color scheme but not the fonts * Firefox (GTK3) do not take anything from the environment Further discussion on https://github.com/NixOS/nixpkgs/issues/152914
This, honestly, looks like an issue with interactions between GTK and NixOS's way of setting up a system, or just a packaging issue in general. From my understanding, this is only happening under a Nix environment, and we haven't gotten similar bug reports for other distros. Tentatively marking as a downstream issue; do reopen if you can reproduce outside of a Nix environment. Just FYI to help you debug it: GTK config isn't managed by env vars, but by gsettings/.inis on Wayland and the xsettingsd/.inis on X11. See also kde-gtk-config.
So I just resolved this for myself, but it was confusing and here is the rough chain of events (also posted to https://github.com/NixOS/nixpkgs/issues/180720#issuecomment-1228334905): - was only happening on Wayland for me - `GTK_THEME=Breeze` (or `Breeze-Dark`) seems to work to fix it on every app I tried - https://github.com/NixOS/nixpkgs/issues/155291#issuecomment-1014772774 made me look at `dconf-editor /org/gnome/desktop/interface`, and shockingly, *only some of the `~/gtk-{3,4}/settings.ini` entries* (that Systems Settings set) were there - notably absent: `gtk-theme` - going into Systems Settings -> Appearance -> Application Style -> GNOME/GTK, then selecting *the same entry* from the dropdown, and clicking Apply (which I didn't expect to become available, since I didn't change entries), fixed it *instantly* (I saw a VSCode Help -> About dialog get the right title bar as I pressed the button) My best guess so far is that something deleted some of the entries (or migrated the `.ini`s but only partially?), but I have no idea what or when. On a different machine (with some shared history) where `dconf` is missing, I don't even have a `~/.config/dconf` at all, so it likely happened only on this one, after switching to Plasma/Wayland. I'm mostly posting this in case other people are searching for how to fix their system: - make sure you have `dconf` - for NixOS specifically: `programs.dconf.enable = true;` (maybe it should be enabled by default for plasma5, just like e.g. kde-gtk-config is?) - run `dconf read /org/gnome/desktop/interface/gtk-theme` to confirm that it is in fact incorrect - go in System Settings and set the Application Style GTK theme *again*