If you are looking for an effect like this:
http://callofthemuse.com
at ATO->Style & configure SIDEBARS->RIGHT sidebar style you would put
HTML Code:
border-left: dashed 0px #CCCCCC;
padding: 10px 10px 10px 10px;
background: #;
this gets rid of the border, puts a 10px padding on each side of the sidebar and makes the background of the sidebar transparent so the page background shows thru. On the example page, the widget containers are also styled with
HTML Code:
margin: 0 0 15px 0;
border: solid 2px #000000;
padding: 0 5px 10px 5px;
background: #DED3BE;
-moz-border-radius: 15px;
-khtml-border-radius: 15px;
-webkit-border-radius: 15px;
border-radius: 15px;