Now that color is set only when it changes, no need to forcedly set it when mode changes.

panel-plugin/netload.c

@@ -390,10 +390,6 @@ static void monitor_set_mode (XfcePanelPlugin *plugin, XfcePanelPluginMode mode,
         }
     }
 
-#if GTK_CHECK_VERSION (3, 20, 0)
-    for (i = 0; i < SUM; i++)
-        set_progressbar_csscolor(global->monitor->status[i], &global->monitor->options.color[i]);
-#endif
     monitor_set_size(plugin, xfce_panel_plugin_get_size(plugin), global);
 
     run_update( global );