Changing the top bar color for all apps

[marios_kstone]

I need to make some visual change to our test Splunk environment in order to make clear that you are in the test environment and not in the production one. The login disclaimer is not enough as for the most time you are actually logged on and with multiple tabs mistakes may happen. I thought to change the top black bar (not the app navigation bar) to a different color but I have been unable to track down the css setting that allows me to do that and where to define it as a global, not per-app, change.
Anyone faced and solved a similar issue?

Thanks

[msivill_splunk]

As alternatives

a) could you have users display with a different name in the bar so "Marios" in production and "TEST - Marios
- TEST" in test

b) override the global CSS so that the screen background is not grey, where the dashboard panels sit on top of. https://answers.splunk.com/answers/11709/css-for-view-higher-priority-than-application-css-and-defau... cover location of global CSS

[marios_kstone]

The "user name" is a nice idea, unfortunately we use the same ldap server for authentication and the same user.
The CSS override is per-app/per dashboard and not global... unless there is some way I couldn't find to globally override the default CSS.