title: How to change the color of the Border of a TextBox when it has focus?
body: <p>In my windows phone app, I have set the border of my Text box to null:
                  </p>
  
  <p>But when it has focus, it still show a blueish color as its border. How can I config that color?
  I tried looking at the template for Text Box, I don't see there is a property for the color of border when it has focus:</p>
  
  <p>Does anyone has any idea if that is changable?</p>
  
  <pre><code>    &lt;Thickness x:Key="TextControlHeaderMarginThemeThickness"&gt;0,0,0,4.8&lt;/Thickness&gt;
      &lt;x:Double x:Key="TextControlThemeMinHeight"&gt;33&lt;/x:Double&gt;
      &lt;x:Double x:Key="ContentControlFontSize"&gt;20.26&lt;/x:Double&gt;
      &lt;SolidColorBrush x:Key="TextBoxDisabledBackgroundThemeBrush" Color="Transparent" /&gt;
      &lt;x:Double x:Key="TextControlBackgroundThemeOpacity"&gt;0.8&lt;/x:Double&gt;
      &lt;x:Double x:Key="TextControlBorderThemeOpacity"&gt;0.8&lt;/x:Double&gt;
      &lt;ControlTemplate x:Key="TextBoxControlTemplate1" TargetType="TextBox"&gt;
          &lt;Grid&gt;
              &lt;VisualStateManager.VisualStateGroups&gt;
                  &lt;VisualStateGroup x:Name="CommonStates"&gt;
                      &lt;VisualState x:Name="Disabled"&gt;
                          &lt;Storyboard&gt;
                              &lt;ObjectAnimationUsingKeyFrames Storyboard.TargetName="BackgroundElement" Storyboard.TargetProperty="Background"&gt;
                                  &lt;DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxDisabledBackgroundThemeBrush}" /&gt;
                              &lt;/ObjectAnimationUsingKeyFrames&gt;
                              &lt;ObjectAnimationUsingKeyFrames Storyboard.TargetName="BorderElement" Storyboard.TargetProperty="BorderBrush"&gt;
                                  &lt;DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxDisabledBorderThemeBrush}" /&gt;
                              &lt;/ObjectAnimationUsingKeyFrames&gt;
                              &lt;ObjectAnimationUsingKeyFrames Storyboard.TargetName="ContentElement" Storyboard.TargetProperty="Foreground"&gt;
                                  &lt;DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxDisabledForegroundThemeBrush}" /&gt;
                              &lt;/ObjectAnimationUsingKeyFrames&gt;
                              &lt;ObjectAnimationUsingKeyFrames Storyboard.TargetName="PlaceholderTextContentPresenter" Storyboard.TargetProperty="Foreground"&gt;
                                  &lt;DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxDisabledForegroundThemeBrush}" /&gt;
                              &lt;/ObjectAnimationUsingKeyFrames&gt;
                          &lt;/Storyboard&gt;
                      &lt;/VisualState&gt;
                      &lt;VisualState x:Name="Normal"&gt;
                          &lt;Storyboard&gt;
                              &lt;DoubleAnimation Storyboard.TargetName="BackgroundElement" Storyboard.TargetProperty="Opacity" Duration="0"
                                  To="{ThemeResource TextControlBackgroundThemeOpacity}" /&gt;
                              &lt;DoubleAnimation Storyboard.TargetName="BorderElement" Storyboard.TargetProperty="Opacity" Duration="0"
                                  To="{ThemeResource TextControlBorderThemeOpacity}" /&gt;
                          &lt;/Storyboard&gt;
                      &lt;/VisualState&gt;
                      &lt;VisualState x:Name="Focused"&gt;
                          &lt;Storyboard&gt;
                              &lt;ObjectAnimationUsingKeyFrames Storyboard.TargetName="BorderElement" Storyboard.TargetProperty="BorderBrush"&gt;
                                  &lt;DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextSelectionHighlightColorThemeBrush}" /&gt;
                              &lt;/ObjectAnimationUsingKeyFrames&gt;
                              &lt;DoubleAnimation Storyboard.TargetName="PlaceholderTextContentPresenter" Storyboard.TargetProperty="Opacity" Duration="0" To="0" /&gt;
                              &lt;ObjectAnimationUsingKeyFrames Storyboard.TargetName="BackgroundElement" Storyboard.TargetProperty="Background"&gt;
                                  &lt;DiscreteObjectKeyFrame KeyTime="0" Value="{ThemeResource TextBoxFocusedBackgroundThemeBrush}" /&gt;
                              &lt;/ObjectAnimationUsingKeyFrames&gt;
                          &lt;/Storyboard&gt;
                      &lt;/VisualState&gt;
                  &lt;/VisualStateGroup&gt;
              &lt;/VisualStateManager.VisualStateGroups&gt;
              &lt;Grid.RowDefinitions&gt;
                  &lt;RowDefinition Height="Auto"/&gt;
                  &lt;RowDefinition Height="*"/&gt;
              &lt;/Grid.RowDefinitions&gt;
              &lt;Border x:Name="BackgroundElement" Grid.Row="1" Background="{TemplateBinding Background}" Margin="{TemplateBinding BorderThickness}" /&gt;
              &lt;Border x:Name="BorderElement" Grid.Row="1" BorderBrush="{TemplateBinding BorderBrush}" BorderThickness="{TemplateBinding BorderThickness}" /&gt;
              &lt;ContentPresenter x:Name="HeaderContentPresenter" Grid.Row="0" Style="{StaticResource HeaderContentPresenterStyle}" Margin="{ThemeResource TextControlHeaderMarginThemeThickness}"
                  Content="{TemplateBinding Header}" ContentTemplate="{TemplateBinding HeaderTemplate}" /&gt;
              &lt;ScrollViewer x:Name="ContentElement" Grid.Row="1" MinHeight="{ThemeResource TextControlThemeMinHeight}"
                  HorizontalScrollMode="{TemplateBinding ScrollViewer.HorizontalScrollMode}"
                  HorizontalScrollBarVisibility="{TemplateBinding ScrollViewer.HorizontalScrollBarVisibility}"
                  VerticalScrollMode="{TemplateBinding ScrollViewer.VerticalScrollMode}"
                  VerticalScrollBarVisibility="{TemplateBinding ScrollViewer.VerticalScrollBarVisibility}"
                  IsHorizontalRailEnabled="{TemplateBinding ScrollViewer.IsHorizontalRailEnabled}"
                  IsVerticalRailEnabled="{TemplateBinding ScrollViewer.IsVerticalRailEnabled}"
                  IsDeferredScrollingEnabled="{TemplateBinding ScrollViewer.IsDeferredScrollingEnabled}" Margin="{TemplateBinding BorderThickness}"
                  Padding="{TemplateBinding Padding}" IsTabStop="False" ZoomMode="Disabled"
                  AutomationProperties.AccessibilityView="Raw"/&gt;
              &lt;ContentControl x:Name="PlaceholderTextContentPresenter" Grid.Row="1" Foreground="{ThemeResource TextBoxPlaceholderTextThemeBrush}"
                  FontSize="{ThemeResource ContentControlFontSize}" Margin="{TemplateBinding BorderThickness}" Padding="{TemplateBinding Padding}"
                  IsTabStop="False" Content="{TemplateBinding PlaceholderText}" /&gt;
          &lt;/Grid&gt;
      &lt;/ControlTemplate&gt;
  </code></pre>