How to apply different style for document tab item header in WPF DockingManager?

<Window x:Class=”_dockingincident.MainWindow"
                 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
                 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                 xmlns:syncfusion="http://schemas.syncfusion.com/wpf"
                 Title="MainWindow" Height="350" Width="525">
     <Grid x:Name="Grid1">
         <syncfusion:DockingManager x:Name="Dockingmanager1"  UseDocumentContainer="True" Grid.Row="1" >
             <syncfusion:DockingManager.DocumentTabControlStyle>
                 <Style TargetType="{x:Type syncfusion:DocumentTabControl}">
                      <Setter Property="TabItemSelectedBackground" Value="Green" />
                 </Style>
             </syncfusion:DockingManager.DocumentTabControlStyle>
             <ContentControl x:Name="content1"  syncfusion:DockingManager.Header="Child1"  syncfusion:DockingManager.State="Document">
                  <syncfusion:DockingManager.DocumentTabItemStyle>
                      <Style TargetType="{x:Type syncfusion:TabItemExt}">
                          <Setter Property="Background" Value="Red"/>
                          <Setter Property="HoverBackground" Value="Transparent"/>
                      </Style>
                   </syncfusion:DockingManager.DocumentTabItemStyle>
              </ContentControl>
              <ContentControl x:Name="content2" syncfusion:DockingManager.Header="Child2" syncfusion:DockingManager.State="Document">
                  <syncfusion:DockingManager.DocumentTabItemStyle>
                      <Style TargetType="{x:Type syncfusion:TabItemExt}">
                          <Setter Property="Background" Value="Blue"/>
                          <Setter Property="HoverBackground" Value="Transparent"/>
                      </Style>
                   </syncfusion:DockingManager.DocumentTabItemStyle>
               </ContentControl>
          </syncfusion:DockingManager>
     </Grid>
</Window>

using Syncfusion.Windows.Tools.Controls;
namespace _dockingincident
{
  /// <summary>
  /// Interaction logic for MainWindow.xaml
  /// </summary>
  public partial class MainWindow : Window
  {
    public MainWindow()
    {
      InitializeComponent();
      DockingManager DockingManager1 = new DockingManager();
      DockingManager1.UseDocumentContainer = true;
      Style style = new Style(typeof(TabControlExt));
      SolidColorBrush brush = new SolidColorBrush();
      brush.Color = Colors.Green;
      style.Setters.Add(new Setter(TabControlExt.TabItemSelectedBackgroundProperty, brush));
      DockingManager.SetDocumentTabControlStyle(DockingManager1, style);
      ContentControl content1 = new ContentControl();
      DockingManager.SetHeader(content1, "Child1");
      DockingManager.SetState(content1,DockState.Document);
      ContentControl content2 = new ContentControl();
      DockingManager.SetHeader(content2, "Child2");
      DockingManager.SetState(content2, DockState.Document);
      DockingManager1.Children.Add(content1);
      DockingManager1.Children.Add(content2);
      Style style1 = new Style(typeof(TabItemExt));
      SolidColorBrush brush1 = new SolidColorBrush();
      brush1.Color = Colors.Red;
      style1.Setters.Add(new Setter(TabItemExt.BackgroundProperty, brush1));
      style1.Setters.Add(new Setter(TabItemExt.HoverBackgroundProperty, brush1));
      style1.Setters.Add(new Setter(TabItemExt.IsSelectedProperty, false));
      DockingManager.SetDocumentTabItemStyle(content1, style1);
      Style style2 = new Style(typeof(TabItemExt));
      SolidColorBrush brush2 = new SolidColorBrush();
      brush2.Color = Colors.Red;
      style1.Setters.Add(new Setter(TabItemExt.BackgroundProperty, brush2));
      style1.Setters.Add(new Setter(TabItemExt.HoverBackgroundProperty, brush2));
      style1.Setters.Add(new Setter(TabItemExt.IsSelectedProperty, false));
      DockingManager.SetDocumentTabItemStyle(content2, style2);
      Grid1.Children.Add(DockingManager1);
    }
  }
}