combine image and solidcolor background for a WPF Form

I have a WPF form I'm building - I want to specify a background image for the window, which is easy enough. However, I also want to specify a color so that the area of the form not covered by the image is white. I've seen some examples that show using two different background brushes, but when I try that VS.NET tells me I can't have multiple brushes.

This is the XAML I'm using

<Window x:Class="Consent.Client.Shell"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:cal="http://www.codeplex.com/CompositeWPF"
    Title="Shell" WindowStyle="None" WindowState="Maximized" FontSize="24">
    <Window.Background>
        <ImageBrush AlignmentX="Left" AlignmentY="Top"  Stretch="None" TileMode="None" ImageSource="logo_header2.png" />
    </Window.Background>
    <ItemsControl Background="White" VerticalAlignment="Center" cal:RegionManager.RegionName="MainRegion" >
    </ItemsControl>
</Window>

This works great for the image, but the background not covered by the image is black. How do I make it white? Changing the image itself is not really an option.

From stackoverflow

• I'm not sure you can combine brushes. You could play around with ImageBrush, or you could forget the "background" and stack the items on top of each other in a Grid:

  <Window x:Class="Consent.Client.Shell"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
          xmlns:cal="http://www.codeplex.com/CompositeWPF"
      Title="Shell" WindowStyle="None" WindowState="Maximized" FontSize="24">
      <Grid>
          <Image Source="logo_header2.png" Stretch="None" VerticalAlignment="Top" />
          <ItemsControl Background="White" VerticalAlignment="Center" cal:RegionManager.RegionName="MainRegion" >
          </ItemsControl>
      </Grid>
  </Window>
  

• Try this (I removed everything not directly relevant to the question to make the code clearer):

  <Window x:Class="Consent.Client.Shell"
          xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
          xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
          Background="White">
     <Grid>
        <Grid.Background>
           <ImageBrush ImageSource="logo_header2.png" />
        </Grid.Background>
        <ItemsControl>
        </ItemsControl>
     </Grid>
  </Window>
  

  Basically, set the window's background to the behind the image color, than put a grid in the window and give the grid you background image, put everything inside the grid instead of directly in the window.