Hi Sadegh
You can edit your templates body colour by adding the following CSS to the end of your templates template.css (../templates/j51_digitalempire/css/template.css)
[code type=css]body {background: url("../images/bg.jpg"

repeat-y scroll 50% 0 #130E0A;}[/code]
Where #130E0A is your background colour.
CiarĂ¡n