It can be important to set the apps background colour, for instance if you are using page transitions.

In App.xmal.cs add this in the OnLaunched() function:

	if (rootFrame == null)
	{
		// Create a Frame to act as the navigation context and navigate to the first page
		rootFrame = new Frame();

		//Set the app background colour behind our page transiions
		SolidColorBrush scb = new SolidColorBrush();
		scb.Color = Windows.UI.Colors.Black;
		rootFrame.Background = scb;