Group Boundaries allow the user to easily see what tasks the Group task encompasses.
This is very useful when you have a deep hierarchy in your schedule/WBS.
The background colour is inherited from the group task and hence will be able to provide instant feedback on what parts of the schedule are late.
This is a user preference so it can be turned on or off.
Where does this preference reside? I cannot seem to find it in “Preferences”, “Project Settings”, or “View Options”.