The Color of the Zebra

A zebra dies and meets St. Peter at the pearly gates. He decided to ask him a question that had been nagging him his whole life. “Peter, am I a white horse with black stripes, or am I a black horse with white stripes?”
Peter is stumped, so he tells the zebra to ask God himself. So the zebra clip clops into heaven, and one day meets God. He finally gets enough courage to approach him and asks the same question he asked at the gates.
God immediately replies “You are what you are, son.”
The zebra is even more confused than ever. After a few days, the zebra runs into Peter once again, and tells him what God told him.
“Oh, you’re a white horse with black stripes!”
The zebra asks Peter how he could have possibly deduced that from God’s answer.
“Well, if you were a black horse with white stripes, he would have told you ‘You is what you is’.”