The inner page layout (the skin) there is a header which displays the page title and has an image background. It is possible to change the image and there are 8 different background to choose from in the DnnContra theme.
You are able to do this by changing 1 class in the skin.asxc file. First open the skin.ascx file located in the root of the theme directory, if you scroll down you will see a section called 'Page title area'. On the first line you should see html like below:
<div class="page-banner banner8">
<!--#include file="layouts/default/page-title.ascx" -->
The class you are going to change is the banner8 class. There are 8 different banners available so you can change the class to: banner1, banner2, banner3, banner4, banner5, banner6, banner7, banner8