Load WPF styles or other Static Resources from an external file or assembly
Solution 1:
Referencing an external ResourceDictionary (XAML File):
<Application.Resources>
<ResourceDictionary Source="MyResources.xaml" />
</Application.Resources>
Referencing an external ResourceDictionary (DLL):
<Application.Resources>
<ResourceDictionary Source="/MyExternalAssembly;component/MyResources.xaml" />
</Application.Resources>