a simple "yum install OpenColorIO" will work on F15 and up and also on EL6 (but only if using the Fedora EPEL repository...)
This should definitely be mentioned in the installation guide - having a nice easy install option before the "Building from source" instructions is a great improvement!
It should also mention the "Homebrew" installation command for OS X ("brew install opencolorio")
I'm happy to add this, as I'm working on other sections of the docs right now