Overlay settings are used to set the color and transparency thereof. For example, as soon as you go over the menu and expand a submenu, you will see that the background becomes darker. You can adjust this here.

Overlay color setting
Choose the overlay color you want to use here (color palette), we recommend just black.

Opacity
Enter the value of the opacity here. This can be set from 0 to 100.
​0 = not visible, 100 = completely covered.