Install4J "Preparing the XXX Installer" dialog using a different look and feel than the installer

What settings are required for the initialization dialog to use the dark LaF?

I created an installer using Install4J 10.0.5 with the following Look and Feel (LaF) settings:

FlatLaf cross platform Look and Feel
Dark or light mode: Always use dark mode
Dark theme: Flat Darcula

Media sets are generated for Windows and Linux.

Upon executing the installer in Windows 10, a progress dialog appears with a message similar to, "Preparing the XXX Installer". This dialog does not use the dark LaF.

When executing the installer in RHEL 7.9, the progress dialog does not appear at all.

All subsequent dialogs correctly use the dark LaF on both Windows and Linux.

Solution

The initial dialog on Windows is not a Java dialog, but a native dialog. On Linux there is no such dialog, because the installer has no native part. As of install4j 10.x, it has no support for dark mode.