Actually I'm not an author of this theme. I've decided to try... if there is no objection. Added comments to < Color > section.
I use this picture as a reference:
In the original file there was an excess line (176) - deleted in new version:
176 <ColorAlias name="lua action button: fill" alias="theme:bg"/>
177 <ColorAlias name="lua action button: fill" alias="widget:bg"/>
a screenshot:
1edc9c5845