Extension to improve the appearance of the sidebar Facebook Messenger™
How to Use:
1. Install the Extension on Opera
2. Open or refresh http://www.messenger.com page
3. That's it!
If you want to use a dark theme, you need a browser that supports "Force Dark Pages", currently only Opera GX supports it. To activate it, open messenger.com manually, and then select the Enforce Dark Theme option from the context menu.