Zebra's stripes come in different patterns and are unique to each animal. It was previously believed that zebras were white animals with black stripes, since some zebras have white underbellies. However further studies have shown, that the animal's background color is actually black, and the white stripes and bellies are additions.
Another interesting fact about Zebra's is that the sound a Zebra makes, sounds like a barking dog! It was just so surprising, I never expected a zebra to sound like that! : )