title: How do I format headers on a WPF Datagrid?
body: <p>I am using the WPF Datagrid from Codeplex.</p>
  
  <p>I am able to style the rows and with the following attributes in the dg:DataGrid element.</p>
  
  <p>But how do I style the Headers? I find 100s of examples on the web which define Styles and use e.g. x:Key="DataGridColumnHeaderStyle" in the Datagrid element, but none of them seem to work for me.</p>
  
  <p>How can I just e.g. change the Datagrid Header background to orange on this DataGrid?</p>
  
  <pre><code>&lt;dg:DataGrid AlternatingRowBackground="#ddd" 
      RowBackground="#eee" 
      Name="theGrid1" 
      VerticalAlignment="Stretch" 
      AutoGenerateColumns="False" 
      BorderBrush="#ddd"&gt;
  ...
  &lt;/dg:DataGrid&gt;
  </code></pre>