network-applet: clean up some insensitive styling

Reuse some of the same styling we use in the power applet for the currently
selected and :insensitive item

data/theme/cinnamon-sass/widgets/_menus.scss

@@ -122,6 +122,8 @@ $menuitem_border_radius: $base_border_radius * 1;
   @extend %heading;
   color: $fg_color;
 
+  &:insensitive { color: $fg_color; }
+
   .popup-inactive-menu-item {
     font-weight: normal;
     color: $fg_color;
@@ -133,3 +135,5 @@ $menuitem_border_radius: $base_border_radius * 1;
 
 // Used to set the color of the signal strength icons in network applet
 .nm-menu-item-icons { spacing: .5em; }
+
+.wireless-active:insensitive { color: red; }

files/usr/share/cinnamon/applets/network@cinnamon.org/applet.js

@@ -649,6 +649,7 @@ NMDevice.prototype = {
         }
         this._activeConnectionItem = new PopupMenu.PopupMenuItem(title, { reactive: false });
         this._activeConnectionItem.setShowDot(true);
+        this._activeConnectionItem.actor.add_style_class_name('popup-device-menu-item');
     },
 
     _deviceStateChanged: function(device, newstate, oldstate, reason) {
@@ -894,6 +895,7 @@ NMDeviceModem.prototype = {
             if (!this.mobileDevice.operator_name)
                 this._operatorItem.actor.hide();
             this.section.addMenuItem(this._operatorItem);
+            this._operatorItem.actor.add_style_class_name('popup-device-menu-item');
         }
 
         NMDevice.prototype._createSection.call(this);
@@ -1603,6 +1605,7 @@ NMDeviceWireless.prototype = {
                                                                               { reactive: false });
         }
         this._activeConnectionItem.setShowDot(true);
+        this._activeConnectionItem.actor.add_style_class_name('popup-device-menu-item');
     },
 
     _createAutomaticConnection: function(apObj) {