Improve drawer menu items

sky/sdk/example/demo_launcher/lib/main.dart

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 import 'package:sky/mojo/activity.dart' as activity;
 import 'package:sky/mojo/asset_bundle.dart';
 import 'package:sky/painting/box_painter.dart';
 import 'package:sky/theme/colors.dart' as colors;
 import 'package:sky/theme/typography.dart' as typography;
 import 'package:sky/widgets/basic.dart';
@@ skipping 87 matching lines @@
       backgroundColor: const Color(0xFF0081C6)
     )
   ),
   new SkyDemo(
     name: 'Sector',
     href: '../../widgets/sector.dart',
     bundle: 'sector.skyx',
     description: 'Demo of alternative layouts',
     textTheme: typography.black,
     decoration: new BoxDecoration(
-      backgroundColor: colors.Black,
+      backgroundColor: colors.black,
       backgroundImage: new BackgroundImage(
         image: _bundle.loadImage('assets/sector_thumbnail.png'),
         fit: BackgroundFit.cover
       )
     )
   ),
   // new SkyDemo(
   //   'Touch Demo', '../../rendering/touch_demo.dart', 'Simple example showing handling of touch events at a low level'),
   new SkyDemo(
     name: 'Minedigger Game',
@@ skipping 67 matching lines @@
           )
         )
       )
     );
   }
 }
 
 void main() {
   runApp(new SkyHome());
 }