Hi!
I download this theme Mac4Lin | Get Mac4Lin at SourceForge.net and when I try to install it, I have a massage that: it looks as if “mac4lin_install_1.0” is not right theme 
Why?
How do you try to install that theme?
Did you run the install script in the source? Mac4Lin_Install_v1.0.sh
From your message I guess you did try to install using a theme manager (gtk theme manager since this is a gnome theme) and you got a message saying that the package is not a theme package.
The opensuse page for this theme is here: Mac4Lin - New releases, discussions, comments etc. - openSUSE Forums