How Justice is Slipped into "The Help"

In The Help, Kathryn Stockett focuses on a racially controlled era, when African Americans still worked for whites and separate bathrooms were constructed outside of homes for maids, because of the fear of catching "Negro diseases". Justice is a complicated issue in this book and Aibileen, Minny, and Miss. Skeeter are searching for the best and safest way for them to tell others about the injustice they've experienced.
Aibileen and Minny are both maids who work for dominant and complex white women, Miss. Celia and Miss. Leefolt. Minny and Aibileen have been working all their life and when Miss. Skeeter asks them to participate in an interview to go in her new book about the ups and downs about working for white women, they are extremely hesitant. Black people can get fired or worse for talking about their white employers behind their backs and Aibileen and Minny would have nothing if they didn't work. There seems to be no justice in the life of an African American because they are so constricted by what they can and cannot do. 
I don't see the white  people in the book as bad, but confused and shaped in a racist society that has influenced their way of life. Justice seems to be the last thing on Miss. Leefolt's mind because she doesn't see Aibileen as a friend even though she has been working for her and her family for several years. 
I think the main thing that upsets me about the injustice in this book is the fact that skin color can keep people away from each other and prevent strong relationships. I already know Minny has given Miss. Hilly, her old employer, a taste of what she considers justice by giving her a cake of something that is supposedly really bad. In Minny's case, her justice was out of revenge, but revenge just escalates problems and now Minny tries to avoid Miss. Hilly on every occasion to avoid starting a bigger problem. If Miss. Skeeter collaborates with Aibileen and Minny to make the book, that justice will be even more powerful because they're speaking out and letting others know what they're feeling.