As the title indicates, an important symbol in the novel is the color purple. Celie first wants to buy a piece of purple clothing for herself, because it is a royal color that she identifies with Shug. Celie's draping of herself in this vibrant, attention-getting, royal color symbolizes her transformation into a person beginning to recognize her own self-worth.
Purple also symbolizes the vibrance and beauty of creation that Celie becomes aware of as she grows into a new sense of self. She writes,
I think it pisses God off if you walk by the color purple in a field somewhere and don't notice it.
As the above quote shows, Celie has learned that humans are meant to appreciate the material world.
Purple symbolizes as well the new concept of God as manifest in the world that Celie develops. She sheds the old patriarchal God that has not served her well. She says that this God cut her off from appreciating the beauty in God's creation, symbolized by the color purple, something she only recently has been able to notice:
Trying to chase that old white man out of my head. I been so busy thinking bout him I never truly notice nothing God make. Not a blade of corn (how it do that?) not the color purple (where it come from?). Not the little wildflowers. Nothing.
Another important symbol in the novel is quilting. Quilting symbolizes, first, female community. Sofia and Celie bond over making a quilt together, a shared activity that moves them from isolation and towards love. Further, the quilts symbolize the way women, working together, can fashion beauty out of the odds and ends and discarded scraps of the world. Patriarchy may only offer women its discards, but these still represent God's creation and are material that women can work with to create comfort, warmth, and joy. Finally, quilts symbolize and mirror the physical beauty of God's creation. As Celie says of a quilt,
The little yellow pieces, look like stars.