Can anyone tell me the name of this book?

Hello!!! In 8th grade my teacher made us read this book that involved Utopia. The story follows the main character, a boy, as he receives his first job in society. He begins to question the ways of a society and when a child is born who must be killed for being different (i think it was because his eyes were a different color) the main character kidnaps him and they leave the society. In the end they freeze to death all alone.