Why expect Chrome to do it for you and what about when you are testing for other browsers, you do test for other browsers hopefully, when you can provide this yourselves with very little effort? Browser plug-in facilities are mostly to provide web functionality to those that can't change the sites.
Simple:
If you have an automatic deployment mechanism, such as deployment through Jenkins or git, you could have the background colour of the whole config page automatically changed in colour depending on the phase deployed to.
Also Simple:
Make the background colour for the settings page, on each sever or in each environment, be a colour loaded from a css pages that is not a part of the deployed application but is present, but different, on the Test & QA servers to the production server.
Nearly As Simple
On the settings page include a little JavaScript to change background or add watermark or warning.
function setColourBasedOnServer(){
if(document.URL.indexOf("TestServer") >= 0){ // Use some string unique to test
document.body.style.background = 'green';
}
if (document.URL.indexOf("QAServer") >= 0){ // Use some string unique to QA
document.body.style.background = 'amber';
}
else { // NOT Test or QA
document.body.style.background = 'white'; // Or some sensible default colour
}
}
And invoke it:
<BODY onload="setColourBasedOnServer();">
