In ./Styles/Colors.xaml I have a bunch of colors like this:

<Color x:Key="IIT_Purple">#6A00FF</Color>

Which I can reference in my platform-non-specific XAML code without any problems, using {StaticResource IIT_Purple}.

However when I try to reference them the same way in ./Platforms/Windows/App.xaml the program hits a break with an unhandled exception:

(Click to enlarge)

If I duplicate the <Color>‘s from ./Styles/Colors.xaml in to ./Platforms/Windows/App.xaml then they work perfectly – but this goes against the DRY/WET principle since it is duplicating the code.

Similarly in ./Platforms/Windows/App.xaml.cs I have had to duplicate the colors again, like so:

var IIT_Purple = Color.FromArgb("#6A00FF").ToWindowsColor();

How can I reference the colors that are in ./Styles/Colors.xaml from within the WinUI platform-specific code please? Both in ./Platforms/Windows/App.xaml as well as ./Platforms/Windows/App.xaml.cs.