改变价值的一定义的依赖性财产编程方式

我想要改变价值的一定义的依赖性财产编程。

这是我的键

<Window.Resources>
      <ResourceDictionary>
         <Style
            x:Key="TreeViewItemStyle"
            TargetType="TreeViewItem">    
            <Style.Triggers>
               <Trigger
                  Property="local:ColorHelper.IsColor"
                  Value="True" >
               <Setter
                  Property="Foreground"
                  Value="{Binding Color}" />
               </Trigger>
               <Trigger
                  Property="local:ColorHelper.IsColor"
                  Value="False" >
               <Setter
                  Property="Foreground"
                  Value="Black" />
               </Trigger>
            </Style.Triggers>
           </Style>
      </ResourceDictionary>
   </Window.Resources>

我想这种风格应用于树视图

<TreeView
           HorizontalAlignment="Stretch"
           Margin="15,65,15,0"
           x:Name="treeView1"
           VerticalAlignment="Stretch"
           ItemContainerStyle="{StaticResource TreeViewItemStyle}"
           ItemTemplate="{StaticResource CheckBoxItemTemplate}"
           Grid.ColumnSpan="1"
           Grid.RowSpan="2"
           Grid.Column="1" />

和颜色的改变值IsColor财产通过一个格：

<CheckBox
                     Name="CHK_Gray"
                     VerticalAlignment="Center"
                     Foreground="DarkGray"
                     Grid.Row="6"
                     Grid.Column="0"
                     Grid.RowSpan="1"
                     Grid.ColumnSpan="2"
                     Unchecked="grayCheckBox_Unchecked"
                     Checked="grayCheckBox_Checked">
                     Show Created Assembly (in Grey)
                  </CheckBox>

依赖性财产是创造这样的：

 public class ColorHelper : DependencyObject
   {
      public static readonly DependencyProperty IsColorProperty = DependencyProperty.Register(
          "IsColor", typeof(bool), typeof(ColorHelper), new PropertyMetadata(false));


      public static void SetIsColor(DependencyObject target, Boolean value)
      {
         target.SetValue(IsColorProperty, value);
      }

      public static bool GetIsColor(DependencyObject target)
      {
         return (bool)target.GetValue(IsColorProperty);
      }
   }

我怎么可以做的检查和未经检查的事件改变的价值IsColor的财产？

private void grayCheckBox_Checked(object sender, RoutedEventArgs e)
  {
     ???
  }
  private void grayCheckBox_Unchecked(object sender, RoutedEventArgs e)
  {
     ???
  }

非常感谢你的帮助！