Signposts can be understood as similar to foreshadowing: concrete signals that point to the direction in which the novel and Celie's life are headed. Signposts in the second half of The Color Purple include the return of Shug, reconnecting with Nettie, Celie starting her own business, and Celie's evolving relationship with God.
A first signpost is the return of Shug in the second half of the novel. Shug is a symbol of light, love, and possibility for Celie. Their kissing is a signpost of the love affair they will have. Shug's return, in general, signals the positive changes that are about to come into Celie's life.
Reuniting with Nettie is another signpost that Celie's future will be far brighter than her past. When she finds what she formerly couldn't believe, that her husband hid Nettie's letter from her, she is able to see Albert for what he has become and to feel a liberating anger towards him. Nellie's grit and positive attitude, as well as her involvement in Marcus Garvey and the idea of Africa, foreshadow Celie's journey there. Between Shug and Nettie, Celie, in the second half of the novel, is beginning to shed her past, find strong women to support her, and take hold of life in a more positive way.
When she moves to Memphis with Shug, Celie starting her own clothes design business is another signpost of her embracing the color of life and her own power. Finally, Celie's evolving relationship with God, in which she is able to move away from the conception of God as an oppressive white patriarch toward an ability to see the divine in the color purple and embrace the feminine as holy, is a signpost of her healing and growth.