Search says I can't change the color of window title and that OS controls that.

It's common for many desktop apps now to have a dark default theme such as Photoshop, Aperture, iMovie, etc. and I'd like that for my app too.

QSS doesn't allow that styling and I see old posts that say it's the OS window manager that controls this, etc. but I can't have an dark themed app with light title bars on it's windows. Also seems toolbars also have the same problem at least on Mac.

What is the best/easiest way to change the color and other aspects of the window or other OS/top-level items?

Thanks,
Brett