Hi Bhargavi,
I don't believe we have anything within ServiceNow as of now but you can use following extension.
a chrome extension called "Environment Marker"
https://chrome.google.com/webstore/detail/environment-marker/ahjhdebcnlgmojdmjnhikhakkghcchkk
you can configure the labels to appear with specific text, color and position.
Please, don't forget to mark my answer as correct if it solves your issue or mark it as helpful if it is relevant for you!
Regards,
Tushar
