Then I'd suggest renaming your current /usr/share/themes/Ambiance/gtk-3.0/apps/gnome-terminal.css to something like /usr/share/themes/Ambiance/gtk-3.0/apps/gnome-terminal.css.ori and then copy the file you downloaded above in to that location.
If you dont like it, delete the new file and rename the original back again.
It's not especially pretty, but it does the job for me.
If you want to provide some feedback on the attached branch that would help.
You can download the relevant CSS for your config (Ambiance for the default theme, Radiance for the alternative lighter theme) from here:
http:// bazaar. launchpad. net/~willcooke/ ubuntu- themes/ terminal- tabs/view/ head:/Ambiance/ gtk-3.0/ apps/gnome- terminal. css
or
http:// bazaar. launchpad. net/~willcooke/ ubuntu- themes/ terminal- tabs/view/ head:/Radiance/ gtk-3.0/ apps/gnome- terminal. css
Then I'd suggest renaming your current /usr/share/ themes/ Ambiance/ gtk-3.0/ apps/gnome- terminal. css to something like /usr/share/ themes/ Ambiance/ gtk-3.0/ apps/gnome- terminal. css.ori and then copy the file you downloaded above in to that location.
If you dont like it, delete the new file and rename the original back again.
It's not especially pretty, but it does the job for me.