Dear Maintainer,

GNOME Terminal 3.16 ignores the org.gnome.terminal.legacy.dark-theme
setting and continues to use the light theme variant for its title bar.
Likewise, using "GTK_THEME=Adwaita:dark gnome-terminal" does not enable
the dark theme variant (this does work for other applications). Enabling
the dark theme globally for all applications using gnome-tweak-tool will
change the terminal theme as expected. Hence it appears to be a problem
with gnome-terminal not supporting per-application theme change.

This bug may or may not be related to #769197 or #779674, but does not
appear to be a duplicate of either.