Not Everything Is Black and White
In The Outsiders, another theme involves the ways in which adolescents tend to see the world in two shades: absolute right and absolute wrong. An important lesson for people to learn as they pass from the teen years into the adult world is that the world rarely takes those "black and white" forms.
In her writing, S.E. Hinton incorporates colors into the story to help the reader see both of the warring groups in a deeper, richer way. In general, the "Soc" kids appear around warm colors, while the "greasers" appear around cooler colors -- and this matches the view that the "Soc" class is on the inside, having gained acceptance, while the "greasers" are stuck outside, still waiting to be found worthy. Note the cold hatred in Darry and Dally's eyes.
When the color white does appear, it is as a sign of ambiguity. Note Dally's hair -- blond to the point of whiteness. Dally is the meanest of the "greasers," but he gives Ponyboy and Johnny money, a gun, and a coat when they need to run. He tries to help the two of them when it's time to pull the children out of the church fire. So clearly, Dally is not all cold inside.