WPF treeviewItem 失去焦点后，怎么让背景色为白色

WPF treeviewItem 失去焦点后，如何让背景色为白色
以下是我的代码，急求大家帮助。

<TreeView.ItemContainerStyle>
 
               <Style TargetType="{x:Type TreeViewItem}">
 
                   <Style.Triggers>
 
                       <Trigger Property="IsFocused" Value="False">
 
                           <Setter Property="IsSelected" Value="False" />
 
                           <Setter Property="Foreground" Value="Red" />
 
                        </Trigger>
 
                   </Style.Triggers>
 
               </Style>
 
           </TreeView.ItemContainerStyle>