Great work, thanks a lot for sharing it with us.
Anyway I don't use it yet on my Ubuntu 19.04 because of incompatibility with my very favorite file manager (Double Commander aka. doublecmd-gtk, installed through apt, not by snap or appimage).
I don't understand what makes a dark theme work with this application or not but I see that Starlabs and Adwaita-dark are theming it perfectly. I don't know the difference with a theme like yours nor which files should be included or modified, sorry to be of no help.
Do you think that this issue with Double Commander could be fixed? I would be glad to use this theme as I really like it.
Here's a concrete example:
Marwaita Dark > https://i.imgur.com/iPPeI5P.png
StarLabs Dark > https://i.imgur.com/FGDgJHI.png
I've posted a message on application's forum to get more informations about the files to customize but nobody answered for now > https://doublecmd.sourceforge.io/forum/viewtopic.php?t=5769