To use it, simply create or edit a database connection, and set the Connection Color to whichever color you choose:
Once set, any and all windows associated with that connection will be outlined in that color. That's it! I already gleefully went through my connection list and associated different colors with different types of connections. For example, our development schemas got green:
While our production schemas got red:
Now, no matter what type of object I am editing, I will instantly know which schema it belongs to based on the color of the border. Simple AND effective!