WPF: Animating a StaticResource updates other controls that use that resource - wpf

Question

I have two TextBoxes that use the same StaticResource for their foreground colour.
When I apply an animation that changes the colour of the first TextBox, the colour on the second TextBox is also changed.
This does not happen if I don't use a StaticResource, so I am guessing that the animation is changing the colour of the brush defined in the resource, rather than the foreground colour on the first TextBox.
Here is the code I am using;
<Page.Resources>
<SolidColorBrush x:Key="TextBrush"
Color="Black" />
<Storyboard x:Key="Glow"
TargetProperty="Foreground.Color"
Storyboard.TargetName="txt1">
<ColorAnimation To="Blue"
Duration="0:0:0.1" />
</Storyboard>
<Storyboard x:Key="Normal"
TargetProperty="Foreground.Color"
Storyboard.TargetName="txt1">
<ColorAnimation To="Yellow"
Duration="0:0:0.1" />
</Storyboard>
</Page.Resources>
<StackPanel>
<StackPanel.Triggers>
<EventTrigger RoutedEvent="StackPanel.MouseEnter">
<BeginStoryboard Storyboard="{StaticResource Glow}" />
</EventTrigger>
<EventTrigger RoutedEvent="StackPanel.MouseLeave">
<BeginStoryboard Storyboard="{StaticResource Normal}" />
</EventTrigger>
</StackPanel.Triggers>
<TextBlock Name="txt1"
Foreground="{StaticResource TextBrush}">Text One</TextBlock>
<TextBlock Name="txt2"
Foreground="{StaticResource TextBrush}">Text Two</TextBlock>
</StackPanel>
Is there anyway around this?
Matt

Answer 1

By using a single StaticResource in the binding, changing the Foreground in your animation will change the resource itself. This behavior is by design, as anything else would require full copies of resources, which would very much reduce the usefulness and benefits of using StaticResource in the first place.
The easy workaround, of course, is to not use a StaticResource here, or to use a separate resource per TextBox.