How do I revert to the previous colour after a ColorAnimation ends inside a DataTrigger?

Question

<DataTemplate>
    <StackPanel Name="stack" Background="PaleTurquoise">
        <Grid>
            <Slider Name="sld" Value="{Binding TimeLeft}" />
        </Grid>
    </StackPanel>

    <DataTemplate.Triggers>
        <DataTrigger Binding="{Binding ElementName=sld, Path=Value}" Value="0">
            <DataTrigger.EnterActions>
                <BeginStoryboard Name="flash">
                    <Storyboard TargetName="stack" Storyboard.TargetProperty="Background.(SolidColorBrush.Color)">
                        <ColorAnimation From="MediumSpringGreen" To="Crimson" Duration="0:0:0.1" AutoReverse="True" RepeatBehavior="0:0:5"/>
                    </Storyboard>
                </BeginStoryboard>
            </DataTrigger.EnterActions>
            <DataTrigger.ExitActions>
                <RemoveStoryboard BeginStoryboardName="flash"/>
            </DataTrigger.ExitActions>
        </DataTrigger>
    </DataTemplate.Triggers>
</DataTemplate>

This is a cut down version of the xaml inside my alarm application. When the value of the slider hits 0 the ColorAnimation is triggered which animates the background of the StackPanel in which the Slider is contained.

However I want the Color of the Background to revert to the previous value (PaleTurquoise) when the flashing ends. How do I accomplish this in xaml?

As a further question, how can I get the DataTrigger to not fire when the application is first loaded even though TimeLeft in my ViewModel is 0 on initialization?

Answer 1

In the end I made a StaticResource for the default colour of the background and put another ColorAnimation after the first one thus:

<ColorAnimation To="{StaticResource alarmBackgroundColour}" BeginTime="0:0:5"/>

To answer the second part of getting the trigger to not fire on startup I hacked around it by making a ValueConverter return 1 for the first call only.

Any better solutions are welcome.