Content background

On Line 601 of style.css:

.full-width-content #inner {
background: url(images/inner.png);
}

That is what is overwriting your setting of the background to white on line 569.

Comment out that block should fix it.

You need a text editor that shows the line numbers. In a jiffy, just press ctrl + F and paste the above code to search for it.

In the meantime, download Notepad++ and have all the glories. here’s the link: http://notepad-plus-plus.org/