Problem
In the code view you don't know the defined scope of a control unless you switch to the Designer view.
I typically make all of my controls on a window private. But in the case where I missed making one private I don't know that unless I go through each control on the window to double check them.
Proposed Solution
In the Code view set the background color of the controls the same way the Properties are colored. You easily see whether you have the controls set to your preferred scope.
Example Workflow
Alternatives Considered
Who Would This Help?
Anyone who doesn't leave all of their controls with a Public scope.