DataTrigger not firing in ListView

I have the below ListView, and the DataTrigger is not firing to change the color when it encounters a null value. The default text I specify from TargetNullValue is returned, but the color is not being changed.

USING:

VS 2012 C# WPF

CONTROL:

<ListView 
                     x:Name="NameListView"
                     HorizontalAlignment="Left" Height="Auto" Margin="37,0,0,0" Width="300"
                     ItemsSource="{Binding Path=Authors}"                
                     SelectedItem="{Binding Path=CurrentItem}"><ListView.View><GridView AllowsColumnReorder="true"
                                      ColumnHeaderToolTip="Information"><GridViewColumn DisplayMemberBinding= "{Binding Path=Title, TargetNullValue='No Title Found'}" 
                                                Header="Title" Width="Auto"><GridViewColumn.CellTemplate><DataTemplate><DataTemplate.Triggers><DataTrigger Binding="{Binding Title}" Value="{x:Null}"><Setter Property="TextBlock.Foreground" Value="Salmon"/></DataTrigger></DataTemplate.Triggers></DataTemplate></GridViewColumn.CellTemplate></GridViewColumn><GridViewColumn DisplayMemberBinding= "{Binding Path=Author, TargetNullValue='No Author Found'}" 
                                                Header="Authors Name" Width="Auto"/><GridViewColumn DisplayMemberBinding= "{Binding Path=TargetNumber, TargetNullValue='No Number Found'}" 
                                                 Header="Target Number" Width="Auto"/></GridView></ListView.View></ListView>

What am I missing?