The top and bottom of my browser has changed from solid gray to pink tinted transparent. I've checked the add ons and there is no theme/persona installed. I've restarted in safe mode and it's still there. I've installed different themes/personas and it will change the area where it says file, edit, view, etc., but the area above that remains pink transparent.

Any ideas how to revert this back to normal? And what is the name of that area anyway?