Is it possible to change the background opacity of the Unity Launcher?
I see you can change the panel opacity, but then the launcher clashes with the panel.
You can use unity-df (a patched launcher)
From the terminal, you can use:
to get the current value for launcher opacity and
to set the launcher opacity to
P:S This way is preferred over any other method that used dconf directly.
If you're running 13.10 you can use Unity Tweak Tool.
Open the "Launcher" category, from there you can use the "Transparency level" slider to adjust the launcher's transparency.
You can also change the launcher's color.