New Post: Can't change border for PropertyItem in PropertyGrid

I am unable to change the border brush and border thickness of the PropertyItem but I can change other things like the background.

<Style TargetType="{x:Type xctk:PropertyItem}">
        <Style.Triggers>
            <Trigger Property="Validation.HasError" Value="True">
                <Setter Property="BorderBrush" Value="Green"></Setter>
                <Setter Property="BorderThickness" Value="10"></Setter>
                <Setter Property="Background" Value="Orange"></Setter>
            </Trigger>
        </Style.Triggers>
    </Style>

When there is an error I get the orange background like I would expect as well as the red border which seems to be the default error style. Nothing happens even if I move the brush and thickness setters outside the triggers.