It would be nice if it would be possible to set the terminal-theme under Preferences->Colors as the systems default-theme. This is for example possible in the gnome-terminal. This could lead to a more coherent desktop-experience.
Igor referenced this bugreport in commit 6cd4fcb05c8503676097eb2658bd3f056aeaa556 Add an option to use system theme colors https://git.xfce.org/apps/xfce4-terminal/commit?id=6cd4fcb05c8503676097eb2658bd3f056aeaa556
Done!
*** Bug 15156 has been marked as a duplicate of this bug. ***