/* Companion Custom CSS over-rides for [ Slightly Damned ]: SDamned  - 1.0 */

.bypostauthor { background: #CD3333; }

body {background: #6E0607;
}

h1, h2, h3, h4 {
font-family:'Arial',sans-serif;
}

#page, #page-wide {
	background: #FFF;
	border-left: solid 1px #000;
	border-right: solid 1px #000;
	border-bottom: solid 1px #000;
	border-top: solid 1px #000;

}

#content-wrapper, #content-wrapper {
	background: #ffffff;
}

#comic {
border: none;
	}

.narrowcolumn, .widecolumn {
	background: #ffffff;
}
Awesome, thanks heaps Zerzix. That worked perfectly.

For those wondering, I added the following code to the theme companion to increase the width of my blog to 620px and have two sidebars both with a 170px width.

/* Blog Column Width */
.narrowcolumn {
width: 740px;
}

/* Left Sidebar Themes */
#sidebar-left {
float: left;
width: 100px;
padding: 5px;
margin: 0;
}

/* Right Sidebar Themes */
#sidebar-right {
float: left;
width: 170px;
padding: 5px;
margin: 0;
}