Need the comments background to be white

I have the site the way I want it but when people leave a comment there is just text and not a solid backgrouns like the posts. Its really hard to see and have been trying to fix a while now. See what I mean here http://mmavalor.com/2009/11/12/matt-hamill-giveaway/. Here is my style.css

/*
Theme Name: Simple Balance 2.2.1
Theme URI: http://blogsessive.com
Description: Simple, highly customizable, well-balanced 3 column theme. More Power. More Style. Your Style!
Tags: fixed width, three columns, simple, control panel, custom layout
Author: Alex Cristache
Author URI: http://blogsessive.com
*/

[huge chunk of code moderated – please use a pastebin or link to file]