Mixing a Data Trigger with a Regular Trigger in an Items Control

I have one trigger set for my ItemsControl that works perfectly:

<DataTemplate.Triggers>
    <Trigger Property="ItemsControl.AlternationIndex" Value="1">
       <Setter Property="Background" Value="LightGray"  TargetName="Foobar"></Setter>
    </Trigger>
</DataTemplate.Triggers>

My problem is that sometimes, I have to interject a "special line" in the list.

I use the following trigger that works to manipulate the controls in the Template:

<Style TargetType="TextBlock">
   <Style.Triggers>
       <DataTrigger Binding="{Binding isHeaderLine}" Value="true">
          <Setter Property="Visibility" Value="Visible"/>
       </DataTrigger>
   </Style.Triggers>
</Style>

This one works well and I get exactly what I want displayed.

Now, my question is that I want to merge them, so that the Special line will get a White background no matter what number in the AlternationIndex it is.

Can this be done?

Here is the complete code:

<ItemsControl  Margin="0 0 0 30" Name="CtrlOrderDetails" AlternationCount="2">
   <ItemsControl.ItemTemplate>
      <DataTemplate>
         <Grid x:Name="Foobar">
            <TextBlock Text="{Binding ProdcutName}"  Margin="0 5 0 5" FontSize="16">
               <TextBlock.Style>
                   <Style TargetType="TextBlock">
                      <Style.Triggers>
                         <DataTrigger Binding="{Binding isHeaderLine}" Value="true">
                           <Setter Property="Visibility" Value="Collapsed"/>
                         </DataTrigger>
                      </Style.Triggers>
                   </Style>
               </TextBlock.Style>
           </TextBlock>
           <TextBlock Text="{Binding headerText}">
              <TextBlock.Style>
                 <Style TargetType="TextBlock">
                    <Setter Property="FontWeight" Value="Bold"></Setter>
                    <Setter Property="FontSize" Value="16"></Setter>
                    <Setter Property="Foreground" Value="Blue"></Setter>
                    <Setter Property="Visibility" Value="Collapsed"/>
                    <Setter Property="Margin" Value="0 10 0 5 "/>
                    <Style.Triggers>
                       <DataTrigger Binding="{Binding isHeaderLine}" Value="true">
                          <Setter Property="Visibility" Value="Visible"/>
                       </DataTrigger>
                    </Style.Triggers>
                 </Style>
             </TextBlock.Style>
           </TextBlock>
       </Grid>
       <DataTemplate.Triggers>
          <Trigger Property="ItemsControl.AlternationIndex" Value="1">
             <Setter Property="Background" Value="LightGray"  TargetName="Foobar"></Setter>
          </Trigger>
       </DataTemplate.Triggers>
    </DataTemplate>
  </ItemsControl.ItemTemplate>
<ItemsControl>

try use the same DataTrigger from Style in DataTemplate, but with a setter for Background

<DataTemplate.Triggers>
  <Trigger Property="ItemsControl.AlternationIndex" Value="1">
     <Setter Property="Background" Value="LightGray" TargetName="Foobar"/>
  </Trigger>

 <DataTrigger Binding="{Binding isHeaderLine}" Value="true">
     <Setter Property="Background" Value="White" TargetName="Foobar"/>
 </DataTrigger>
</DataTemplate.Triggers>