I've looked up on internet themes for MPGH and I didn't find a non-bugged one. So I took up the Chrome's console and started trying to edit the CSS until I got this:
Everything is fixed to be applied with the dark theme and the pattern interface is just endearing, IMO. If anyone has any idea to improve the theme or wants to report some bugs regarding this, please post here or PM me.
Mozilla signed my extension so I can host it, Chrome didn't for copyright reason (

I don't understand the actual reason).
Here you can find the theme:
http://rodionprojects.000webhostapp.com/
Please, rate below with a post and with a good argumentation!
I'm also going to build up a material theme, just when I'll have all the ideas I'll need. If anyone has a CSS to propose I'll consider it.
Enjoy!