"What do you see as our biggest problem, Mr. Griffin?" Mr. Gayle asked. "Lack of unity." "That's it," said the elderly man who ran the cafe. "Until we as a race can learn to rise together, we'll never get anywhere. That's our trouble. We work against one another instead of together. Now you take dark N****es like you, Mr. Griffin, and me," he went on, "We're old Uncle Toms to our people, no matter how much education and morals we've got. No, you have to be almost a mulatto, have your hair conked and all slicked out and look like a Valentino. Then the N**** will look up to you. You've got class. Isn't that a pitiful hero-type?" (8.162)
We'll help you out with this quote by defining two slang terms. Conked out hair was hair that had been straightened by a chemical called congolene. It looked like this. And when Mr. Gayle refers to a Valentino, he's talking about Rudolph Valentino, who was an old school heartthrob (with straight hair).