TabbedPage tab bar color

I could not find any method to set the tab bar color.
Maybe implement a custom renderer is a good idea, the code I write below on android platform, it crash;
Does the ViewGroup I should use in this issue???

public class MyTabbedPageRenderer : TabbedRenderer
    {
        protected override void OnElementChanged(ElementChangedEventArgs<TabbedPage> e)
        {
            base.OnElementChanged(e);
            if (e.OldElement == null)
            {
                var tabhost = ViewGroup as TabHost;
            }
        }
    }