Imagine having a heart-to-heart with a fifth grader. Got it? (This might be easy if you happen to be a fifth grader.) That's the tone of Opal's voice. Which makes sense, because she's telling the story just one year after it happened. And since our girl is sweet (most of the time), optimistic and self-assured (at least with Winn-Dixie at her side), so is her voice.
When Opal first sees Winn-Dixie tackle the store manager, she has no doubt he is "having a real good time" (1.4), and "you could tell that all he wanted to do was get face-to-face with the manager and thank him for the good time he was having" (1.6).
Keep in mind, she's never met the mutt in her life. And he's big. And ugly. But that doesn't matter.
For Opal, it's a glass half-full kind of world. Take her job, for example. She tells Otis:
"I'm real trustworthy. […] I'm new in town, but my daddy is a preacher, […] so I'm real honest. But the only thing is, Winn-Dixie, my dog, he would have to come inside with me; because if we get separated for too long, he starts to howl something terrible."
"Gertrude don't like dogs," sad Otis. […] "That Gertrude. The parrot." […]
"She might like Winn-Dixie," I told Otis. "Almost everybody does. Maybe he could come inside and meet her, and if the two of them get along, then could I have the job?"
"Maybe," Otis mumbled. He looked down at the counter again.
So I went and opened the door, and Winn-Dixie came trotting on inside the store. (8.13-20)
Nothing is too hard for Opal and Winn-Dixie. How's that for confidence?
While the general tone is Opal's confident, optimistic voice, the tone changes a bit when she gets talking with her friends Gloria and Miss Franny. They each have a little more experience under their belts, and that sometimes darkens Opal's mood just a little. But not in a bad way; in more of a mature way.
When Gloria waxes nostalgic and sad, telling Opal about the Mistake Tree, Opal's voice also gets wistful. Take a look at it:
I stayed where I was and studied the tree. I wondered if my mama, wherever she was, had a tree full of bottles; and I wondered if I was a ghost to her, the same way she sometimes seemed like a ghost to me. (14.44)
Or, here's another example. Miss Franny has just told her about Littmus W. Block's losses, and Opal's tone changes.
Winn-Dixie started to snore, and I nudged him with my foot to try to make him quit. I wanted to hear the rest of the story. It was important to me to hear how Littmus survived after losing everything he loved (16.30).
She's a little less happy-go-lucky now, and a little more eager and even a little desperate to figure out how she can learn from Littmus's experience.
Okay, let's bring it home: after the final thunderstorm, all the tones melt together like egg-salad sandwiches in the rain. Opal tells us confidently that Amanda "didn't look pinch-faced at all" (26.29). She also mentions wistfully that the Littmus Lozenge in her mouth opened up "like a flower blooming, all sweet and sad" (26.33).
Sweetness and sadness. That's Opal's tone for ya.