At last its working. Thanks :)
<Window.Resources>
<Style x:Key="ButtonStyle" TargetType="{x:Type Button}">
<Setter Property="Background">
<Setter.Value>
<SolidColorBrush Color="Transparent"/>
</Setter.Value>
</Setter>
<Style.Triggers>
<DataTrigger Binding="{Binding RelativeSource={RelativeSource AncestorType=Window}, Path=DataContext.Notification}" Value="True">
<DataTrigger.EnterActions>
<BeginStoryboard Name="StartBlinking">
<Storyboard>
<ColorAnimation Storyboard.TargetProperty="(Background).(SolidColorBrush.Color)" To="Orange" Duration="00:00:00.4" RepeatBehavior="Forever" AutoReverse="True"/>
</Storyboard>
</BeginStoryboard>
</DataTrigger.EnterActions>
</DataTrigger>
<DataTrigger Binding="{Binding RelativeSource={RelativeSource AncestorType=Window}, Path=DataContext.Notification}" Value="False">
<DataTrigger.EnterActions>
<RemoveStoryboard BeginStoryboardName="StartBlinking"/>
</DataTrigger.EnterActions>
</DataTrigger>
</Style.Triggers>
</Style>