Styling a NavigationPage

I'm trying to style a navigation page. I'd like to set the BarBackgroundColor property to white. I've done the following in the xaml for the content page. I am guessing that the contentpage can't reach up to the Navigation Page. Any suggestions on this? Have I done something incredibly stupid? Do I need to apply this style in a different place?

<ContentPage.Resources>







</ContentPage.Resources>

Thanks for your time.

Wally