As noted in the version history under 1.0.0.15, Quick Access/Home does not always reflect changes to pinned folder icons. When you browse to the applicable top level folder, the icon for the folder has indeed been updated.

Starting with version 1.1 of Windows 11 Folder Color Changer, the app will automatically unpin and repin these folders and force a refresh. Unfortunately, as a side effect, this will change the pinned folder order.