src/Tools/Graphview/graph_panel.scala

       refresh()
     }
     tooltip = "Use editor font and colors for painting"
   }
 
-  private val colorations = new Button { action = Action("Colorations") { color_dialog.open } }
-  private val filters = new Button { action = Action("Filters") { mutator_dialog.open } }
+  private val colorations = new Button { action = Action("Colorations") { color_dialog.open() } }
+  private val filters = new Button { action = Action("Filters") { mutator_dialog.open() } }
 
   private val controls =
     Wrap_Panel(
       List(show_content, show_arrow_heads, show_dummies,
         save_image, zoom, fit_window, update_layout, editor_style)) // FIXME colorations, filters