REPLACE YOUR
body {
font: $(body.font);
color: $(body.text.color);
background: $(body.background);
}
with this one
body {
font: $(body.font);
color: $(body.text.color);
background: #f4cccc url(
http://themes.googleusercontent.com/image?
id=0BwVBOzw_-hbMMDZjM2Q4YjctMTY2OC00ZGU2LWJjZDYtODVjOGRiOThlMGQ3)
repeat-x fixed center center;
}
And you can also change the image url...