@FreeFun: To be honest, I've never wanted to implement the dark mode. That's something that imo an operating system should do. Not individual applications. Because when individual applications do implement it, without (complete) support from the operating system, you end up with problems like this. Edit: As of December 2020, Windows API still do not have documented support for the dark mode.
But people asked so much, despite my concerns, for WinSCP to implement at least PARTIAL support for the dark mode, that I yielded. Those people are now happy. But I'm getting an (expected) backlash from others, who complain, that if WinSCP does support the dark mode, it has support it perfectly. What was never my goal, as I knew that Windows are not ready for the perfect support of the dark mode.