The Color Purple

I do believe that the screenplay of The Color Purple takes away from the narrative of the actual novel. I read the book a while ago, but it was after the fact that I had seen the film. Don't get me wrong, the film is very powerful and inspirational but did the film actually capture the characters of Suge, Ceelie, and Sophia? Or did the film exaggerate on the characters of Mister and Harpo?