Adapted from the L.M. Montgomery books, Kevin Sullivan and Joe Wiesenfeld’s screenplay, Anne of Green Gables is said to be the only "true to the book", Anne. In 1985, after it’s very first airing, Bill Musselwhite of the Calgary Herald wrote, "It is truly an excellent film, partly because of the acting and directing and partially because everyone concerned dedicated themselves to being true to the book. Montgomery would be pleased."
If you read the book first and then see the movie adaptation, it will give you the impression that both are the same. However, the movie actually starts at a different period in Anne’s life. This is because Sullivan and Wiesenfeld wanted to add drama to the book. In doing so, they used stories that were episodic to build strong relationships between the characters. For example, the green hair scene was moved closer to the beginning in the movie, helping to bring Marilla and Anne closer together. Another difference in the movie is Marilla’s relationship with Gilbert Blythe’s father which was much more expanded in the movie than the book. All of these changes were also instrumental in creating a compelling dramatic version that still captured the authenticity of Montgomery’s original work.