Yes, you'll just need to edit the fp02.css file. Find this part:

/* Styles for posts */
.bPosts {
	vertical-align: top;
	float: left;
	width: 66%;
	overflow: hidden;
}

and change it to this:

/* Styles for posts */
.bPosts {
	vertical-align: top;
	float: left;
	width: 66%;
	overflow: hidden;
        background: #00F;
}

Change the background color to whatever you want. Then find this part:

.bSideItem {
	margin-right: 20px;
	margin-left: 10px;
	margin-top: 8px;
	margin-bottom: 8px;
	border: 1px dashed #CCCCCC;
	padding: 8px;
}

and change it to this:

.bSideItem {
	margin-right: 20px;
	margin-left: 10px;
	margin-top: 8px;
	margin-bottom: 8px;
	border: 1px dashed #CCCCCC;
	padding: 8px;
        background: #0F0;
}

Perfect. Thanks so much.