Multi-Rename Tool shows a white flash on dark mode

[AGlezB]

Using dark mode on Win 10 when you open Multi-Rename Tool it first shows in Normal mode and then switches to Dark mode.
That creates a white flash which is very anoying at 300 nits and blinding at higher levels.

Suggestion: apply the theme before showing the form.

[ghisler(Author)]

I don't think that this can be done, but I will try.

[AGlezB]

All I can ask for

[ghisler(Author)]

I made quite a lot of changes, not only for the multi-rename tool but also for other dialogs and the main window. Please let me know if you still get white flashes somewhere.