[macOS] Instructions for enabling App-wide Dark Mode do not work

[sidneys]

Description

The current recommendations on how to enable the application-wide Dark Mode (on macOS) for JDownloader2 doesn't work, resulting in a light title bar.

Environment

macOS Mojave 10.14.6 (18G4032)

[admojica]

I agree, the instructions does not work for MacOS.

[Vinylwalk3r]

Is it just the title bar that doesn't work? Or is it the entire theme?