Aurora is fluid width with optional left and right sidebars.

Download from drupal.org/project/aurora. This version is 6.x-1.0 from 2008-Dec-27, a 92.66 KB download.

Wave did not detect accessibility errors. The W3C validation passed this theme as XHTML 1.0 Strict. Cynthia Says this theme is US 508 compliant as far as a computer can check but found some links creating WAI problems. The stricter Total Validator validation found a couple of problems. There should not be any white space at the start or end of an attribute's value:
<div class="menu withprimary withsecondary ">

The following link is indistinguishable from a link in the menu and should be made unique with a title.
<a href="http://www.drupal.org/">Drupal</a>

CSS validation produced the following 4 errors at both levels 2.1 and 3.
URI : http://d-theme.com/sites/all/themes/aurora/layout.css
32 #sidebar-right Parse Error .margin-left: -190px;
33 #sidebar-right Parse Error /* IE7 Fix */ }
URI : http://d-theme.com/sites/all/themes/aurora/layout.css?n
32 #sidebar-right Parse Error .margin-left: -190px;
33 #sidebar-right Parse Error /* IE7 Fix */ }

Enhancements

This theme is a bit busy with the decoration distracting from the content. The book styling is lost in the colour on colour. you can edit the CSS to remove the background from the body element and set all body margins to zero. The medium blue border disappears.

The next step is to make the header and footer the same blue as the sizebars. you can delete the backgrounds from the header and footer then move the background-color from the sidebar to the body. You are left with some annoying black borders that should be easy to delete.