Todd Kleinhans does not believe that green is good:
Far too many times, I have seen DBA(s) and others have this false sense that if the Agent run status shows green, then everything must be ok.
Click through for a funny story about a gas station robbery and examples of how a SQL Agent job can report success but actually fail. You also see this a lot with replication or tasks that are asynchronous in nature: the task is reporting that we successfully started whatever operation, but that doesn’t mean the operation itself succeeded.