Using css you'll be able to change any element or section of the site. If the site if set to full width sections in the layout editor you'll be able to use css to extend the background color to the full width of the site.
Looking at that line of css you have, the .content-pad part is whats instructing it to stay inside the content area. Remove that and the color will go full width.
Most of the css inside the Framework will follow the format of '.section-' followed by the name of the section. So for the footer you're looking at
We'd advise you to use firebug to find the names of the sections so you can edit them in the css. If you've not used css before then check out
which will give you an overview