When selecting the 'Calibrate' button in the Color Settings dialog, when run within the Settings Manager container, causes an error: (xfce4-color-settings:9069): Gtk-CRITICAL **: 07:57:28.584: gtk_widget_get_window: assertion 'GTK_IS_WIDGET (widget)' failed (xfce4-settings-manager:8796): xfce4-settings-manager-CRITICAL **: 07:57:29.385: pluggable dialog "xfce4-color-settings" crashed When running xfce4-color-settings standalone, the 'Calibrate' button properly brings up the calibration dialog.
Simon Steinbeiss referenced this bugreport in commit dddc379ef46fee97c26648f21bffd94516404cbc color: Fix crash when launching gcm in plugged dialog (Bug #15426) https://git.xfce.org/xfce/xfce4-settings/commit?id=dddc379ef46fee97c26648f21bffd94516404cbc
Thanks for noticing and reporting the bug!