I have a StackedBarSeries in Silverlight 4 charting (latest release).

I have created a DataPointStyle called MyDataPointStyle for a custom tooltip. By itself this breaks the standard palette used for the different bars.

I've applied a custom palette - as described in David Anson's blog to the chart. However when I have the DataPointStyle set for my SeriesDefinition objects it does not use this palette.

I'm not sure what I'm missing - but David specifically says :

... it enables the use of DynamicResource (currently only supported by the WPF platform) to let users customize their DataPointStyle without inadvertently losing the default/custom Palette colors. (Note: A very popular request!)

Unfortunately I'm inadvertently losing these colors - and I can't see why?

    <chartingToolkit:Chart.Palette>
        <dataviz:ResourceDictionaryCollection>
            <ResourceDictionary>
                <Style x:Key="DataPointStyle" TargetType="Control">
                    <Setter Property="Background" Value="Blue"/>
                </Style>
            </ResourceDictionary>
            <ResourceDictionary>
                <Style x:Key="DataPointStyle" TargetType="Control">
                    <Setter Property="Background" Value="Green"/>
                </Style>
            </ResourceDictionary>
            <ResourceDictionary>
                <Style x:Key="DataPointStyle" TargetType="Control">
                    <Setter Property="Background" Value="Red"/>
                </Style>
            </ResourceDictionary>
        </dataviz:ResourceDictionaryCollection>
    </chartingToolkit:Chart.Palette>

    <chartingToolkit:Chart.Series>

        <chartingToolkit:StackedBarSeries>

            <chartingToolkit:SeriesDefinition
                        IndependentValueBinding="{Binding SKU}" 
                        DependentValueBinding="{Binding Qty}" 
                        DataPointStyle="{StaticResource MyDataPointStyle}"
                        Title="Regular"/>

            <chartingToolkit:SeriesDefinition
                        IndependentValueBinding="{Binding SKU}" 
                        DependentValueBinding="{Binding Qty}" 
                        DataPointStyle="{StaticResource MyDataPointStyle}"
                        Title="FSP Orders"/>

            <chartingToolkit:StackedBarSeries.IndependentAxis>
                <chartingToolkit:CategoryAxis Title="SKU" Orientation="Y" FontStyle="Italic" AxisLabelStyle="{StaticResource LeftAxisStyle}"/>
            </chartingToolkit:StackedBarSeries.IndependentAxis>

                <chartingToolkit:StackedBarSeries.DependentAxis>
                <chartingToolkit:LinearAxis Orientation="X" ExtendRangeToOrigin="True" Minimum="0" ShowGridLines="True" />
            </chartingToolkit:StackedBarSeries.DependentAxis>

        </chartingToolkit:StackedBarSeries >
    </chartingToolkit:Chart.Series>

</chartingToolkit:Chart>