Designer: Display environment one is connected to

Is there an easy way to display and preferably permanently display the environment one is in? To me this is a security feature. I am thinking along colouring like many DB tools allow.

Nope, there is none. I double checked with SAP support. The data store pane displays the repository one is connected to. If you need to know the server you can look in the environment section of Designer in the options. Or start the switch object library dialogue.