Problem with Custom Renderer

Following a guide online, I've created a custom renderer for a navigation page with the goal of changing the font and color of a toolbar caption.

To start, I set up a custom NavigationPage in the PCL as follows:

public class FontNavigationPage : NavigationPage
{
    public FontNavigationPage(Page root) : base(root)
    {
        BarBackgroundColor = Color.FromHex("#7DBBD9");
        BarTextColor = Color.Blue;
    }
}

Then the custom renderer for Droid:

[assembly: ExportRenderer(typeof(FontNavigationPage), typeof(FontNavigationPageRenderer))]

namespace XXXXXXXXX.Droid.Renderers
{
public class FontNavigationPageRenderer : NavigationPageRenderer
{
private Android.Support.V7.Widget.Toolbar toolbar;

    public override void OnViewAdded(Android.Views.View child)
    {
        base.OnViewAdded(child);
        if (child.GetType() == typeof(Android.Support.V7.Widget.Toolbar))
        {
            toolbar = (Android.Support.V7.Widget.Toolbar)child;
            toolbar.ChildViewAdded += Toolbar_ChildViewAdded;
        }
    }

    void Toolbar_ChildViewAdded(object sender, ChildViewAddedEventArgs e)
    {
        var view = e.Child.GetType();

        if (e.Child.GetType() == typeof(Android.Widget.TextView))
        {
            var textView = (Android.Widget.TextView)e.Child;
            var spaceFont = Typeface.CreateFromAsset(Xamarin.Forms.Forms.Context.ApplicationContext.Assets, "Lusitana-Regular.ttf");
            textView.Typeface = spaceFont;
            toolbar.ChildViewAdded -= Toolbar_ChildViewAdded;
        }
        //If your app is not using the AppCompatTextView, you don't need this check
        if (e.Child.GetType() == typeof(Android.Support.V7.Widget.AppCompatTextView))
        {
            var textView = (Android.Support.V7.Widget.AppCompatTextView)e.Child;
            var spaceFont = Typeface.CreateFromAsset(Xamarin.Forms.Forms.Context.ApplicationContext.Assets, "Lusitana-Regular.ttf");
            textView.Typeface = spaceFont;
            toolbar.ChildViewAdded -= Toolbar_ChildViewAdded;
        }
    }
}

}

This works in that the toolbar caption appears in the desired custom font.

However, I cannot change the color of the type. I thought that changing BarTextColor = Color.Blue; would do the job, but it has no effect. The text remains dark blue.

Can anyone suggest how to change the textcolor?

Thanks