What is the different about the atmosphere in Montgomery?

When John arrives in Montgomery, he decides to stop taking his medication for a while to lighten his skin. After a few days, he became white again and he noticed a great change between the way he was treated as a white man and the way he was treated as a black man. John feels contradicted, enjoying the freedom he had as a white man and yet hating the fact that he was looked at with suspicion by the black men. In a way, John feels as if he had betrayed the black community by letting his skin become white again.