Bud's first image of the Hooverville near Flint gives a clue to this:
"And there were more people sitting around than I first thought, too...They were all the colors you could think of, black, white, and brown..."
Because need is the great equalizer, the people that Bud and Bugs encounter during their night in Hooverville were all the same color--dirt poor. Ironically, the one hint of racism in this chapter occurs when Bud asks about a white family that is sitting apart from the rest of the group. He asks Deza if they are not allowed to sit around the big fire because their baby is sick and crying.
The girls responds that someone had taken the family food and blankets earlier, but had been rebuffed with the man's remark, "Thank you very much, but we're white people. We ain't in need of a handout." From this the reader can infer that even at the very edge of extremity, the white man needed to feel superior to the Blacks in the camp. His only means of doing so was to refuse their help, even though it meant greater suffering for himself and his family.