SlickEdit looks the same (as if you're not running on this version of Windows) for everything except the Open/Save As dialogs. The Open/Save As dialogs seem to use dark mode for most of it but not for all the controls near the bottom. This appears to be intentionally done by Microsoft (not a bug). If you run NotePad and bring up the open dialog, the bottom controls do not all use dark mode. This is an odd decision by Microsoft.
We tested on build 17682.
SlickEdit also uses the built-in Windows change directory dialog. Oddly, Windows does not use dark mode when this dialog is displayed.The rest of the dialogs SlickEdit uses are Qt dialogs and are not affected by the new dark mode.