Symbolism, Imagery, Allegory
In the Flint Hooverville, the campfire is more than just a place for folks to gather and listen to music or chit-chat. The campfire is a real melting pot of diversity. As Bud notes about the people there, "They were all the colors you could think of, black, white and brown, but the fire made everyone look like they were different shades of orange. There were dark orange folks sitting next to medium orange folks sitting next to light orange folks" (8.77).
The campfire unites all of the shanty townspeople together by erasing their skin color, turning them all into humans illuminated by the firelight. Everyone in the shanty town is in the same boat: they're all poor and homeless and just struggling to get by. Race doesn't (or shouldn't) matter here—but take a look at the Race section in "Themes" to read more about how Bud, Not Buddy handles race—because everyone is suffering in the same way, and everyone is in it together.