Many times we install a theme gtk that we like but over time we discover that there is some detail that we do not like, the color of the menu, the size of the icons, the width of the scroll bars, or things of that type.
En Gnome we have an application that will allow us, in a simple and graphic way, to modify many elements of our theme gtk, and your name is Gnome-Color-Chooser.
To install it, we use Synaptic or in a terminal we put:
$ sudo aptitude install gnome-color-chooser
Now we just have to play with the settings a bit and if we like the result, we can export the settings in format .gnomecc.
If we liked the changes and we want to return to the initial configuration, we delete the configuration file:
$ rm ~/.gtkrc-2.0-gnome-color-chooser
and later we open the file .gtkrc-2.0 in our home, and we eliminate the line:
include ".gtkrc-2.0-gnome-color-chooser"
and we restart nautilus:
$ nautilus -q