How to customize the appearance of BackstageTab in WPF Ribbon control?

<syncfusion:Ribbon x:Name="_ribbon" VerticalAlignment="Top">
     <syncfusion:RibbonTab Caption="HOME"  IsChecked="True">
          <syncfusion:RibbonBar Name="New" Width="90"  Header="New">
               <syncfusion:RibbonButton SizeForm="Large" Label="New Email"/>
               <syncfusion:DropDownButton SizeForm="Large" Label="New Items">
                    <syncfusion:DropDownMenuItem Header="Task"/>
               </syncfusion:DropDownButton>
          </syncfusion:RibbonBar>
          <syncfusion:RibbonBar Name="Delete" Width="130"  Header="Delete">
               <syncfusion:RibbonButton Label="Ignore"/>
               <syncfusion:SplitButton Label="Clean Up">
                    <syncfusion:DropDownMenuItem Header="Clean Up Folder"/>
               </syncfusion:SplitButton>
          </syncfusion:RibbonBar>
     </syncfusion:RibbonTab>
     <syncfusion:RibbonTab Caption="SEND/RCEIVE"  IsChecked="False"/>
     <syncfusion:RibbonTab Caption="FOLDER"  IsChecked="False"/>
     <syncfusion:RibbonTab Caption="VIEW"  IsChecked="False"/>
            
     <syncfusion:Ribbon.BackStage>
          <syncfusion:Backstage SelectedTabItemForeground="Red">
               <syncfusion:BackstageTabItem  Header="Info">
                    <StackPanel>
                         <TextBlock FontSize="20" Text="Account Information"/>
                         <TextBlock FontSize="12" Text="[email protected]"/>
                    </StackPanel>
               </syncfusion:BackstageTabItem>
               <syncfusion:BackstageTabItem Header="Open" />
               <syncfusion:BackStageCommandButton Header="Save" />
               <syncfusion:BackStageCommandButton Header="SaveAttachments" />
               <syncfusion:BackstageTabItem Header="Print" />
               <syncfusion:BackstageTabItem Header="OfficeAccount" />
               <syncfusion:BackStageCommandButton Header="Options" />
               <syncfusion:BackStageCommandButton Header="Exit" />
          </syncfusion:Backstage>
     </syncfusion:Ribbon.BackStage>
</syncfusion:Ribbon>