I've looked through Generic.xaml and ThemeResources.xaml in the following path:
C:\Program Files (x86)\Windows Kits\8.0\Include\WinRT\Xaml\Design
However, they don't seem to contain a resource key that I can use in order to retrieve the color of the current scheme selected in the Windows 8 start screen.
The color I am trying to retrieve through a DynamicResource in the XAML is seen visually below, to demonstrate my point.