How to remove background pattern from every cell without removing background color in Excel?

A cell in Excel can have a background color, or it can have a pattern applied in the background with a “foreground” color to the pattern, or it can have both.

combinations of background color and colored patterns

interface for setting background color and pattern, in Excel v16.91 for macOS

In an enormous worksheet with many cells with varying desirable background colors, I want to remove the pattern, if applied.

If I select all cells and choose “Automatic” for the Pattern color, it shows the current pattern using black. If I change the Pattern style to the “white” square, which represents a transparent pattern, there is no pattern seen on any cells…but all grid lines are “hidden” (overridden with white?) for all those cells the worksheet:

repeating the first image, with no more patterns applied, and light blue background color preserved, but grid lines gone

Is there any way to remove patterns while preserving grid lines and background colors across all selected cells?

I’m not looking for a scripting-based solution; my goal is to be able to “highlight” cells for executives using patterns, but then make it very easy to for the execs to completely remove with a few clicks.