Using themes with FSharpx

[cna]

I have a simple FSharpx WPF application. I am trying to use the standard RoyalTheme.

<ResourceDictionary.MergedDictionaries>
        <ResourceDictionary Source="/PresentationFramework.Luna;component/themes/Luna.normalcolor.xaml" />
</ResourceDictionary.MergedDictionaries>

When I hit F5, I get the following error message:

A first chance exception of type 'System.Windows.Markup.XamlParseException' occurred in PresentationFramework.dll

Additional information: 'Set property 'System.Windows.ResourceDictionary.Source' threw an exception.' Line number '12' and line position '37'.

I have been able to get this to work in C#, but I am not sure what I am doing wrong over here.

Any help is much appreciated. Regards

Chris