You can also solve this with simple JavaScript code inside a HTML snippet in your main layout page.
Something like:
var url = $(location).attr('href');
if(document.URL.indexOf("localhost") != -1)
{$("div.Bar").css( 'background-color','#ffffff');}
else if(document.URL.indexOf("test") != -1)
{$("div.Bar").css( 'background-color','#eeeeee');}
else if(document.URL.indexOf("accp") != -1)
{$("div.Bar").css( 'background-color','#dddddd');}
Will do the trick.. It checks the URL of your window and based on parts of the URL (localhost, text, accp) it will set the background.
Swathi,
You can accomplish this with the StyleSheetSwitcher widget from the App Store.
Mike
EDIT: Just noticed you are on 4.7.1. This widget works from 5.19 forward, so you'll have to upgrade your app to use it.