example panel transparency
For example 100% transparency...
A useful option if you are using transparency is the option just below - Transparency Maximized Toggle (called Opaque panel for maximized windows in Unity-Tweak-Tool)
Switching on this option will not display the top panel as transparent if the window is maximised i.e. with 100% transparency but this toggle switch-on:
Nautilus is maximised and therefore the top-bar does not remain transparent.
The panel transparency can be defined with unity-tweak-tool
(click to install)
The panel transparency can now be defined in MyUnity