title: Xamarin Forms Tabbed page cannot change tab background color
body: <p>I have a Xamarin.Forms tabbed page. When I do the following:</p>
  
  <pre><code>public partial class MainPage : TabbedPage
  {
      public MainPage()
      {
          InitializeComponent();
  
          BarTextColor = Color.White;
          BarBackgroundColor = Color.FromHex("#3F51B5");
          Children.Add(new Batches() { Title = "Batches"});
          Children.Add(new Track() { Title = "Track"});
      }
  }
  </code></pre>
  
  <p>I can change the BarTextColor properly, in this case, it does change to white. However, I cannot set the BarBackgroundColor. As you can see in the snippet, it should be a blue color but it is not, it is white. How can I change the background of just the tabs? There is another background property but it sets the background color of the whole page, not just the tab. </p>
  
  <p>Also, related, how do you change the underline color of the selected tab? I cannot find a property for that and by default, it is a hot pink color. </p>
  
  <p>Thanks!</p>