Is there a way to have a visual difference so that it is clear you are working in a test and/or acceptance environment?
During the release process users are often having multiple applications up-and-running. While they are performing tests they may also be doing work in the production environment. Having the same look-and-feel will make it inevitable that production-data is entered in the test-environment or vice versa, resulting in a production-environment with inaccurate data.
By giving, for instance, a different color to menu's and background this could be improved.