My current GTK popups look like this - note it takes the dark ambiance colour theme.

In GTK3.8 and later there are GTKMenuButtons - the popup looks like this - note it looks like it uses the button styling cues.

I like this style and I want my application popups to look the same so there is a better look - integration and feel.
I know I can override the background colour of the popup using this snippet of python code:
style = button.get_style_context() color = style.get_background_color(Gtk.StateFlags.NORMAL) popup_menu.override_background_color(Gtk.StateFlags.NORMAL, color)
It looks like this if I apply the button background colour.

I've no idea how to apply the button font colour to the popup.
More importantly there is that annoying black border - 1px wide?
Thus to my question - am I attempting this the correct way (overriding theme properties) or can I somehow apply the CSS styling of one widget (the button or the button popup) to the popup so I can mimic the menubutton popup styling?
More information - the GTKMenuButton source gtkmenubutton.c doesnt have any theming controls for the popup, thus I'm at a loss how the menubutton popup gets its theme.
