The "Black" will have a slight performance advantage over the "Blue", but the difference won't be night and day. As jnkweaver already mentioned the main difference would be the warranty. And also the fact that the model you are comparing aren't the same size, you get twice more space with the black.
I see, Well for space wise I really wouldn't need more than 500GB of disk space. Right now i only have 300GB of disk space and I still get about 130GB free for what i am doing. But say I only needed a 2 year warranty would you recommend that I go with the caviar blue? Thank you for your time by the way.