I am trying to make animated borderbrush in WPF application. I would like the 2 colors to "move" all over borderbrush using LinearGradientBrush

<Border
    CornerRadius="15"
    BorderThickness="3">

    <Border.Background>
    #222222
    </Border.Background>

    <Border.BorderBrush>
    <LinearGradientBrush StartPoint="0,0" EndPoint="1,1" Opacity="0.9">
    <GradientStop Color="#f51111" Offset="0.3" />
    <GradientStop Color="#f59211" Offset="0.7" />
    </LinearGradientBrush>
    </Border.BorderBrush>

    </Border>