/* Use a background image for the toolbars and statusbar */
   toolbox, menupopup, .tabbrowser-tabs, tooltip, #FindToolbar, menulist,
#popup-internal-box,
#FindToolbar > .toolbarbutton-text, window statusbarpanel{
   -moz-appearance: none !important;
    background-image: url("file:///yourhoice.jpg") !important;
  } 
  
/* Add background to Customize window and other windows  */
#CustomizeToolbarWindow, #modelist, .menulist-dropmarker, #addBookmarkDialog,
#browser 
{ -moz-appearance: none !important;
background-image: url("file:///yourhoice.jpg") !important; 
}