WPF Button Change Background during Click - wpf

Question

This should be simple, therefore it is something I am missing. I need to change the background color of the a button during the click only. So if a user click the button for 2 days, then the color changes during that two day period. Once the user is done clicking it returns to the normal color. Figured this would solve my issue:
<Style x:Key="MyButtonStyle" TargetType="Button">
<Setter Property="Background" Value="Red"/>
<Setter Property="Button.Effect">
<Setter.Value>
<DropShadowEffect Color="Black" Direction="320" ShadowDepth="3" BlurRadius="5" Opacity="0.5" />
</Setter.Value>
</Setter>
<Style.Triggers>
<Trigger Property="IsPressed" Value="True">
<Setter Property="Button.Background" Value="Purple" />
<Setter Property="Button.Effect">
<Setter.Value>
<DropShadowEffect Color="Black" Direction="320" ShadowDepth="0" BlurRadius="0" Opacity="0" />
</Setter.Value>
</Setter>
</Trigger>
</Style.Triggers>
Now I know the IsPressed does work as the DropShadowEffect work correctly during the press. However the color does not change. The only reason I could think why is that IsMouseOver is taking priority over IsPressed. If this is the case how can I get the two events to "work together?"
Now before people start linking me to this;
WPF changing button background on click or this Change Button Background color on EventTrigger in WPF or this Change Button Background color on EventTrigger in WPF
Yes those change the color of the button but irrespective on the users click time. As stated above I only want it effected during the actual user's click, like the DropShadowEffect

Answer 1

ahhh, I was right! The problem was in fact that IsMouseOver and IsPressed where not getting along! Here is the fix;
<Style x:Key="NewButton" TargetType="Button">
<Setter Property="Background" Value="Red"/>
<Setter Property="Button.Effect">
<Setter.Value>
<DropShadowEffect Color="Black" Direction="320" ShadowDepth="3" BlurRadius="5" Opacity="0.5" />
</Setter.Value>
</Setter>
<Style.Triggers>
<MultiTrigger>
<MultiTrigger.Conditions>
<Condition Property="IsPressed" Value="False" />
<Condition Property="IsMouseOver" Value="True" />
</MultiTrigger.Conditions>
<Setter Property="Background" Value="Green" />
</MultiTrigger>
<Trigger Property="IsPressed" Value="True">
<Setter Property="Button.Background" Value="Purple" />
<Setter Property="Button.Effect">
<Setter.Value>
<DropShadowEffect Color="Black" Direction="320" ShadowDepth="0" BlurRadius="0" Opacity="0" />
</Setter.Value>
</Setter>
</Trigger>
</Style.Triggers>