Setting the opacity of a box
Select the box you want to adjust.
In the right panel, select the [Box] tab.
If the panel is closed, open the right panel.
In the Box tab, go to the [Appearance] menu and adjust the value in the [Opacity] field.
The default value is 1. As the value approaches 0, the element becomes more transparent. A parent box's opacity also affects all child elements inside it.
opacity translucent see-through transparent transparency