Unfortunately, Microsoft Windows does not support dark mode for Win32/Win64 applications.
The required info/functions for Dark mode are only exposed to UWP applications 😞 

To mimic dark mode we'd need (from what I have read) a dark theme - like back in the old Windows XP days.
I honestly have zero experience with mixing that with the new Dark Mode in Windows 10.

So far I have only been able to detect (quite sketchy method) dark mode vs light mode, and I'd be able to change a few controls to different colors.
However, quite a few controls cannot be changed, so the application would look terrible (mix of light and dark). 😞

If you found anything that can be helpful in this, then please let me know - I'd love dark mode for my applications.

Thanks. :)