New Post: Customise AvalonDock style

<xcad:DockingManager  DocumentPaneControlStyle="{StaticResource MyDocumentPaneControlStyle}">

using( System.IO.FileStream fs = new System.IO.FileStream( fileName, System.IO.FileMode.Open ) )
      {
        dic = (ResourceDictionary)System.Windows.Markup.XamlReader.Load( fs );
        Application.Current.Resources.MergedDictionaries.Add( dic );
        _dockingManager.DocumentPaneControlStyle = Application.Current.Resources[ "MyDocumentPaneControlStyle" ] as Style;
      }