Racism and colorism
The most obvious message in the book is about racism, as the motive of the book is a black man waking up one day as a white man. His life then turns around, new opportunities presenting themselves, solely based on his skin color. This shows they bias and the racism that people in the book have to their own race, and the prejudices that are apparent in the society.
The female role
In addition to changing race, there is a man name Igoni that changes sexuality. He becomes a female, also seeing the changes of expectations the world has to the different sexes. Also in Furo's life, women are accessories to the men, not because they have to be, but because it is an easier way of life, and they enjoy it. However, this way of living is in stark contrast to the feminism is mainstream western media today.
Staying true
Staying true to oneself, even during change, is something that both Igoni and Furo struggle with as they change. Furo totally forgets where he came from, and begins acting in a way he world despise had he still been a black man. He wishes to erase his old identity to embrace his new one, forgetting the people he has left behind.