In Ubuntu 12.10, tabbed interfaces such as in gnome-terminal under unity it is difficult to visually distinguish the selected tab from the unselected ones.
Modify ~/.config/gtk-3.0/gtk.css
to solve this problem.
TerminalWindow .notebook tab {
background-color: #D1D0CE;
}
TerminalWindow .notebook tab:active {
background-color: #FFF5EE;
}