How to remove/edit username from threaded comments

[sbatabyal]

Hi there,
I am unable to remove/edit the username from threaded comments. I tried editing/deleting username in Options-general, but it doesn't seem to work. Any help would be appreciated. Also is there a way to change the background color of the comment like a sticky note. I know there is a add note feature available, but I really want to use the threaded comments for its functionality of replying back and forth.
Username to be removed threaded comment.JPG