SUMMARY In X11 applications written using libhandy ignore the system theme always using Adwaita, in Wayland the bug is not reproduced STEPS TO REPRODUCE 1. Run for example gnome-disks or yelp OBSERVED RESULT The application ignores the system theme with this warning in the console (gnome-disks:1391): Handy-WARNING **: Using GtkSettings:gtk-application-prefer-dark-theme together with HdyStyleManager is unsupported. Please use HdyStyleManager:color-scheme instead. EXPECTED RESULT The application follows the theme of the system SOFTWARE/OS VERSIONS Linux: Arch Linux KDE Plasma Version: 6.0.4 KDE Frameworks Version: 6.2.0 Qt Version: 6.7.0 Xsettingsd Version: 1.0.2 Graphics Platform: X11 ADDITIONAL INFORMATION Downgrade kde-gtk-config to version 5.27.80 helps.