Why is menu item greyed out (faded) on the AAM Backend Menu tab?

While managing access to the Backend Menu, certain menu items appear to be faded or greyed out. This is a visual indication that currently managed role or user does not have explicitly assigned capability that grants access to the menu item.

For the example, on the following screenshot, the "Media" menu requires upload_files capability.

To solve this issue, you can grant the capability on the "Capabilities" tab. However, beware of the potential security issue with granting WordPress core capabilities. For more information refer to the Beware of recycled capabilities risk.