Hello E., and all,
Perhaps because this theme should be used by dark background, as:
If that can help,Regards.
Then if you want use on light background, you can add some style after theme command, as:
Here is the expected result:
And finally, there is this not-very-documented feature which works only for FontText:
The fontcolor is choosen depending on the background.
Black backgroundWhite background
We should probably update themes with this feature.
Good... To be add to the todo list of theme enhancement...