Advanced mate menu opacity

Hello,
I'm would like to configure some opacity on the advanced mate menu but I can't figure out how to do It.

I'm using Macro (adaptive compositor) as window manager.
Thanks

I don't believe you can anymore I think it was broken for a while so eventually they removed it

I saw a post on how to do it editing the theme css file under .menu section, but It was for mint mate and I couldn't get it to work either.

I hope someone know a way to do it.