grid.css

/* main grid: graph + panels & bars
 * --------------------------------
 *  html, body
 *  #topbar
 *  #toolbar
 *  #sidebar
 *  #graph-zone
 *  #graph-panels
 *  #graph-div
 *  #hidden-elements
 */

#hidden-elements {
  display: none;
}

#sigma-contnr {
  background-color: #44b;
}

#sidebar {
  background-color: #2e2;
}

#toolbar {
  background-color: #e22;
}

#topbar {
  background-color: #c94;
}

html, body {
   background-color: #eee;
}