Why do we need to know about Miss Emily's hair changing color in "A Rose for Emily"?
In "A Rose for Emily," two of the major elements of the story are evolution and time. The story spans most of Miss Emily's adult life, and the narrative voice of the townspeople charts the public view of Miss Emily over the course of many years. As a young woman, Miss Emily was sheltered by her father, and after his death, she was left to take care of herself. But Emily has never let go of the past, and moments like her refusal to pay her taxes based on a decision that was made a decade ago suggest that she continues to hold onto her past life. Her relationship with Homer Barron marks an opportunity for Miss Emily to change her life for the better, but after he breaks off their relationship, Miss Emily seems to not be able to recover from the loss. The change in hair color is symbolic of the passing of time, and an indicator of the irony that although Emily refuses to acknowledge the passing of time, she is powerless to stop time and change. The hair is also crucial to the plot in that the hair that is found next to Homer's body is the link to the reader's understanding that Emily has been lying with the dead body to keep herself close to Homer.
Moreover, given that Emily's hair is the final item left near her dead beloved at the end of the story and an indicator of her secret predilection for communing with the dead (necrophilia) it is important to note that her iron grey hair is the item that indicates this major twist in plot at the end.
The hair colour directly correlates to different stages in Miss Emily's life, the author also uses it to relate to her health. When the author refers to her as fat, he adds that her hair is turning grey. Later on as the years pass, her hair is referred to as pepper and salt which progress more towards grey as she ages. At the end of her life, in her 70s, her hair is described as vigorous iron grey and compared to the hair of an active man.