Feature summary (what you would like to be able to do and where):
The default visual appearance when you are logged in vs logged out should make it obvious which you are. It's not enough to have something change in the toolbar; nobody notices that. It should be something like a different background color.
Use case(s) (list the steps that you performed to discover that problem, and describe the actual underlying problem which you want to solve. Do not describe only a solution):
Users who normally edit from accounts occasionally get logged out by accident and inadvertently leak their IP addresses because they didn't realize they were logged out until it was too late. T372702 has increased the frequency of this happening but it's not the only cause, I'm aware of several such incidents recently, which required intervention from an oversighter to suppress the leaked IP.
Benefits (why should this be implemented?):
People will be less likely to leak confidential information by accident.
