As the story begins, it is Sunday morning in rural Georgia, 1909. "Po' chil" (Poor child) Celie, 14 years old and pregnant for the second time, is playing a clapping game with her beloved sister Nettie (Huckleberry Pie). When she comes to church with her sister and their Pa, Celie goes into labor before the service ends (Mysterious Ways). Later, Pa takes Celie's baby from her arms (Somebody Gonna Love You), saying he is going to get rid of it, "same as the last one," and that she better not tell anybody except God what happened. Celie asks God for a sign, something that will let her know what is happening to her.
A few years later, when a local farmer, Mister, needs a wife to take care of his children, Pa says Nettie is too young, but offers him Celie instead, and throws a cow into a bargain. Although the girls vow never to be parted (Our Prayer), Celie goes with Mister to save Nettie's dreams of becoming a teacher. As the local Church Ladies cluck their approval (That Fine Mister), Mister's field hands introduce Celie to her life of hard work at Mister's (Big Dog). Nettie arrives one day, having fled from Pa's lecherous attentions, and asks if she can stay. Mister agrees, but then attacks Nettie on her way to school. When she fights back, he throws her off his property, swearing that the girls will never see each other again (Lily of the Field). Nettie promises to write to Celie as she is cast away from Mister's home. However, when Celie attempts to open the mailbox, Mister promptly rebuffs her, threatening her with death if she ever touches it again.
Mister's son, Harpo, grows up and soon brings home Sofia, a proud and strong-willed woman (Dear God - Sofia) whom he loves and later marries. But eventually, Harpo tires of being bossed around by Sofia. Mister tells him he has to beat Sofia if he wants her to mind. Even Celie, who has endured such abuse from Mister, agrees this is the only way to make a woman "jump when he says to." But Sofia gives as good as she gets (A Tree Named Sofia), and is victorious in beating Harpo instead. Angered by Celie's suggestion, she confronts her (Hell No!), but her anger subsides when Sofia realizes how much Celie has suffered from Mister's cruelty. Not long after that, Sofia's sisters arrive to take her away. Sofia tries to convince Celie to come with her, but she declines. Left alone, Harpo turns his home into a juke joint and hires a new waitress, Squeak, to work there (Brown Betty). Love-stricken, Squeak soon moves in with Harpo.
The whole town prepares for the arrival of Shug Avery, a sexy singer who is Mister's longtime lover (Shug Avery Comin' to Town). But when Shug arrives, she is in such bad shape that in spite of local disapproval (All We've Got to Say), Mister brings her home where Celie nurses her back to health (Dear God - Shug). As Celie takes care of Shug, she begins to experience feelings of affection and tenderness for the first time, as Shug befriends her (Too Beautiful for Words). When Shug sings at Harpo's Juke Joint (Push Da Button), Sofia returns with her new boyfriend and gets into a fight with Squeak (Uh Oh!). In Mister's house, Shug and Celie explore their newfound love for each other (What About Love?). Shug gives Celie a letter she found from "someone in Africa, goin' by the stamps." Celie recognizes Nettie's handwriting and knows instantly that her beloved sister is alive (Act I Finale).
Celie discovers the rest of the numerous letters that Mister has hidden over the years, and learns that Nettie traveled to Africa with the missionary family that also adopted Celie’s babies, and that they are now residing in an African refugee camp (African Homeland). Meanwhile, in Georgia, Sofia has been beaten and thrown into jail for punching the mayor. (When his wife asks Sofia to be her maid, and Sofia refuses, the mayor decides to intervene and is then subjected to Sofia’s harsh temper.) Celie goes to the jail to comfort her, and learns that Sofia will have to serve out her sentence in the custody of the Mayor’s wife, thus reducing her to the very thing she fought so hard against. Twelve years later, Sofia and Shug both return home for Easter. Shug discovers the extent of Celie’s anger towards God (The Color Purple) and invites her to come live with her and her new husband in Memphis.
After Easter dinner (Church Ladies’ Easter), Celie tells Mister that she is leaving. He protests and she finally confronts him about his cruel treatment of her over the years (I Curse You, Mister). Squeak is off to Memphis also, stating that she wants to sing. Harpo defends her choice to his father, and long after they leave, he invites Sofia to come back and live at the Juke Joint, reconciling with her in the process. Soon, Mister begins to feel the effect of Celie’s curse. He’s drunk nearly all of the time, and is shunned by everyone. Harpo challenges his father to make things right with Celie, and Mister attempts to understand what that might mean (Mister's Song - Celie’s Curse).
At Shug’s house in Memphis, Celie discovers that she has a natural gift for making pants. When she inherits the house she once lived and grew up in, she goes home and starts a business selling her unique designs (Miss Celie’s Pants). Mister tries to help Sofia’s sickly youngest child Henrietta, and even Celie has to admit that Mister is trying to change. Harpo and Sofia are spending a pleasant night at home (Any Little Thing) when Mister comes to tell them that he has found Nettie, but that she is having some difficulty getting home from Africa. Shug tells Celie that she has fallen in love with a young flute player, and asks her to let her have one last fling with him (What About Love? - Reprise). Walking home, Celie realizes that she isn’t destroyed by this, and feels a deep love for herself, for the very first time (I’m Here).
1949. As the whole community is gathered for a Fourth of July picnic at Celie’s home, Celie hears a car horn, then a familiar song from her childhood. Nettie runs towards the house, with Celie’s adult children following close behind. Mister and Shug have made this reunion possible, and Celie thanks them, and God, for the safe return of her family (The Color Purple"- Reprise).