Darkness

Darkness seems to be very prevalent throughout the book, aside from the fact that it's in the title. Everything in the book seems to be dark; Africa and England are both described as gloomy and dreary even when the sun is shining. In the dark, we cannot see. It is similar to the book because in imperialism, we fail to see and understand other peoples and their lives and their culture, and failing to form some kind of bond or connection with one another.