Hide the grey window placement

[burowolswijk]

I made an assembly of a wood frame with plasterboard.
And a window placed in it.
The window is hosted on a not visible wall.
The wall is placed at the front of the wood frame.

But when I turn on the Consistent Color in the assembly view a grey rectangle is shown, in the same size as the window.

I also made a section after the window/hidden wall (so the window is not visible anymore).
But the grey rectangle is still being shown.

How can I remove or hide this rectangle?

[burowolswijk · Accepted solution]

I already found it.

You can hide the opening cut in projection.

Select the opening cut - and turn transparent on in elevation