How to change color of top bar in Gnome 3.8

Question

I have updated to ubuntu 13.04 and install gnome 3.8. I have some questions how to customize it. It now looks like this:

What confusing me:

1. I can't find how to change color of top bar, I found how to change theme for windows, but it didn't affect on top bar.
2. Some app have app bar both on top and bottom bar (on screenshot - its Firefox). I want top bar have no app bar.
3. It seems for me that after gnome 2 in 3.8 there is less usefull space for window, I dodn`t know what exactly wrong, but may be in previous version there were not so many bars?

Answer 1

For not having a 'Appbar' at the top in certain Applications, you can use

https://extensions.gnome.org/extension/354/maximus/

But you have to change the config file in

~/.local/share/gnome-extension/.../..json

and enable Gnome 3.8 Support. Then you can enable a Whitelist / Blacklist.