The color yellow is the most important symbol in the novel, as the title suggests, and is most often linked to the character of Rayona, especially the image of the yellow raft moored offshore in the lake at Bearpaw Lake State Park. The symbolic color yellow informs many of the novel's themes, including how perceptions are individualized, how reality shatters illusions, and how characters seek feelings of permanence.
The most apparent use of yellow as a symbol is the yellow raft anchored in Bearpaw Lake. Before Rayona swims to the raft, her life has been anything but conventional. She's had to face a reversal of roles concerning her mother, Christine, who acts more like a child than Rayona does. Also, Rayona has been stung many times by racism, both overtly and passively, because of her dual heritage: Her mother is Indian, her father black.
It is on the yellow raft that Rayona feels at peace — initially — with herself. Leaving Father Tom on the shore, she swims to the raft and then suns herself on it. Note that the raft apparently expands the universe for Rayona, a universe that so far has included racism and a feeling of displacement: "I pull myself over the side and lie on the sun-warmed dry boards, panting and soaking up the heat. The silence is wide as the sky." However, the calm that Rayona experiences on the yellow raft is shattered by Father Tom's arrival. Lying next to Rayona, Father Tom jerks his hips against her. Perhaps as a defense against Father Tom's advances, her enters a dreamlike state: "In my dream I move with him, pin him to me with my strong arms, search for his face with my mouth." Ultimately, then, the yellow raft is deceptive: Rayona is as much at risk on it as she was before. The raft provided an initial sense of security that Father Tom violates.
The yellow raft also symbolizes escape for Rayona. She first sees Ellen DeMarco as Ellen is diving into the water off the raft. Unfortunately, the yellow raft in this episode is unhealthy for Rayona because she takes refuge in an illusory world in which she idealizes the perfect life that she assumes Ellen has. Even the way that Ellen gets onto the raft seems perfect: "She hoists herself onto the yellow boards in one smooth, strong motion." On the raft, Ellen is everything that Rayona wants to be. Hers is the picture-perfect world that Rayona's is not. Rayona, comparing herself to Ellen on the yellow raft, falls short of perfection, which Ellen symbolizes: "I'm afraid to see anything more, to see something wrong, something out of place, something to ruin the picture. . . . In that moment she's everything I'm not but ought to be." Here, then, the raft symbolizes what Rayona would like to be but isn't. However, Rayona's self-image is destructive, which the yellow of the raft reinforces in her mind.
The security that the yellow raft symbolizes for Rayona is broken at the beginning of Chapter 7 when Rayona must face up to the many lies that she's created about her own life. At the beginning of this Chapter, she tells Evelyn, who just so happens to be wearing a yellow blouse, her real personal history. Whereas Rayona thinks that Evelyn will reject her after Evelyn learns the truth about Rayona, Rayona in fact assumes control of her life because she tells someone about it. Telling her story makes it real for her. But before she actually tells Evelyn her life story, Rayona tries one last time to deny who she is and counts on the yellow raft to help her. She thinks to herself, "I'm stopped, halfway down the trail, with my eyes fixed on the empty yellow raft floating in the blue waters of Bearpaw Lake. Somewhere in my mind I've decided that if I stare at it hard enough it will launch me out of my present troubles." The "trapdoor" that the yellow raft represents to Rayona is an illusion that Evelyn dispels; Rayona must take control of her life if she's to make anything out of it, and the yellow-bloused Evelyn is the one person who helps Rayona acknowledge who she is and the life that she's led thus far.
For Christine, the color yellow at first is associated with failure, but at the end of her narrative section, it symbolizes the peace that she eventually finds in herself and the world. Growing up, Christine faces the challenge of crossing a naturally made yellow stone bridge on a dare that she herself makes. However, she's unable to cross the bridge alone, and her brother, Lee, comes to her aid. Faced with her own failure, from that point on she leads a reckless life of abandon.
Only at the end of her narrative section, having reaffirmed her relationships with Rayona, Dayton, Ida, and the memory of Lee, does the color yellow symbolize the peace of mind that Christine has craved so often throughout her life. Reunited with Rayona, Christine and her daughter return home to Dayton's after having eaten lunch together. During the meal, Christine privately acknowledges the mistakes that she's made and the hurt that she's caused the people whom she cares for. After giving Rayona her prized turtle ring, an act that symbolizes her own permanence in Rayona's life, Christine dons yellow-tinted sunglasses for the ride home: "When I put them on, they turned the world yellow as an old photograph." The world as an old photograph is comforting to Christine, for she, like Rayona, has found her place in the world and feels more comfortable about who she is. The "old photograph" symbolizes the fact that Christine has finally accepted her past for what it is: a mixture of good and mostly bad times during which she acted irresponsibly and selfishly but now has a better, more healthy grasp of. Here, then, yellow symbolizes peace, but not the illusory peace that the yellow raft symbolized for Rayona. Peace here is real, a feeling that everything will work out for the better.