Accepted AnswerLook in the mod_superpanel/assets/css/superpanel.css
background: none repeat scroll 0 0 #272727;
#272727must be chnaged to what color you need. If your template allows adding extension custom.css file then you can add that code in your templates custom.css file.
In the next revision , I would be adding one or two styles, so i would be interested to know your thoughts and suggestions.