Describe your idea:
Since the jadx-gui uses FlatIJLookAndFeelInfo as the application themes, it is possible to synchronize the app themes and the code editor themes.

FlatIJLookAndFeelInfo(Name, ThemeClass, isDark)

How I see it

You just need to add 2 new constants
currentDarkTheme responsible for storing the values of the current dark theme of the editor
and currentLightTheme, respectively

if (flatIJLookAndFeelInfo.isDark()){
    editorTheme = currentDarkTheme;
} else {
    editorTheme = currentLightTheme;
}

And update the UI accordingly

I would like to add this myself, but I am an Android developer, and have no experience with Swing and desktop applications at all
I would be glad if it would be added