Public bug reported: Firefox doesn't use Adwaita's theme for it. See the screenshot.
I don't use vanilla GNOME on other distributions so I'm not entirely sure what the correct behaviour is but pretty sure Firefox is not supposed to be using the Yaru(?) theme? I have the communitheme snap (0.1 (1171)) installed. ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: gnome-session 3.28.1-0ubuntu3 ProcVersionSignature: Ubuntu 4.15.0-34.37-generic 4.15.18 Uname: Linux 4.15.0-34-generic x86_64 ApportVersion: 2.20.9-0ubuntu7.3 Architecture: amd64 CurrentDesktop: GNOME Date: Mon Sep 17 11:17:45 2018 InstallationDate: Installed on 2017-08-03 (409 days ago) InstallationMedia: Ubuntu 17.04 "Zesty Zapus" - Release amd64 (20170412) SourcePackage: gnome-session UpgradeStatus: Upgraded to bionic on 2018-04-22 (148 days ago) ** Affects: gnome-session (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug bionic wayland-session -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-session in Ubuntu. https://bugs.launchpad.net/bugs/1792910 Title: Firefox doesn't use the session's theme To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-session/+bug/1792910/+subscriptions -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs