tonystones
Hi
yes you can change this image.
The original code is defined in the css/template.css file
#gkBg {
background: #111 url('../images/decor/bg.png') center top repeat scroll;
-webkit-transition: all 350ms;
-moz-transition: all 350ms;
-o-transition: all 350ms;
transition: all 350ms;
-ms-transition: all 350ms;
}