How to assign backgrounds to chat rows

Hi again,

i’m actually on the Facebook-alike-chat-module and i tried to assign two different background colors like #000 for me and #fff for the person i’m chatting with, i also tried to remove my avatar from the chat row (since i know how i look like :p) and keep the one in the row from the other person, and as you may already be suspecting i failed miserably.

Tried to find the necessary parts with the site inspector but bad luck at least for now.

any clues for me please?