Invisible Man is a story about a young, black, educated, southern man who arrives in New York City and begins to see reality and his place in it differently. He struggles to make his idealism real, but he is met with absurdity and dishonesty around every corner.
The narrator's observations are not happy ones, and his idealism is quickly and relentlessly threatened by his disappointment with human nature—both black and white. The book has an underlying subtle humor that is dark and wistful. Ellison also uses irony, both verbal and situational, to create humor. Ellison mocks his characters and employs caricature, puns, and parody—all forms of satire—to humorous effect.
One example of humor is his description of the paint factory and his observation about the roles of white and black people in society. The topic is serious—that of the loss of power, voice, and even the physical presence of black people in a loud, overbearing, predominantly white society. The narrator is invisible, but in the paint factory he watches all day as the white paint needs its little stream of black to get the shade of white correct. Somehow, the black disappears, and the well of paint looks just as white as it did prior to any additives. The sign over the factory says, "Keep America pure with Liberty Paints." The reference to liberty (in the context of slavery) is also ironic.
The narrator often uses names to get points across. Several of the minor characters have names that subtly denigrate them. Wrestrum, for example, sounds suspiciously like "restroom," while Tobitt, who tries to make himself seem bigger than he actually is, sounds like "two-bit." These are subtle, but they do make fun of how seriously they take themselves. The narrator is a very serious person, but he easily sees through others' facades of pretense and importance, so he also mocks himself.
Another example of humor is how the narrator expresses truth through offhand sayings because he is afraid to be honest and knows honesty is dangerous. He says, "All it takes to get along in this here man's town is a little shit, grit and mother-wit."