Titlebar color?

Hey guys! Just bought the Groupy software!
It's pretty good, but I'm super annoyed by having another huge white titlebar above the original chrome titlebar (it takes so much space :O)

Is there an option to make the title bar smaller, or at least in a darker color?
I know there's the "combine when possible" option, but as the name suggests, it's not always possible lol

TL;DR - Is it possible to:
a ) make titlebar smaller/disappear?
or
b ) to change the color to be a bit darker?

Thanks!

edit: Oh btw! is there a guide that explains all the different settings in Groupy? I don't understand what some of them do!