I gave this a try. In theory, it does the following tests:

1. If there's a [Logging]Theme line in plus.ini, set to either Light or Dark, that theme is used.
2. Otherwise, if you're running Windows 10 or 11, it uses your default brightness setting for apps. (This setting was not present in earlier versions of Windows.)
3. Otherwise, it uses the traditional colors (Light).

In practice, I've only tested this on exactly one computer, so let me know how this looks.

Oh, also I removed the near-useless "About" menu option, and changed the bootup code so the JJ2 window goes in front of the chatlogger window.