Shortly after arriving at the Calendar Sister's home, Lily overhears August and June talking about her and she becomes angry because June seems to dislike Lily because she is "white." In this scene in the novel, Lily describes something she calls "righte

In Chapter Five, June insisting to August that Lily and Rosaleen were lying about their backgrounds. August agrees, but she insists that the Boatwrights can offer help. June also is discontent with Lily staying in their house because she is white.

‘But she’s white, August.’
This was a great revelation—not that I was white but that it seemed like June might not want me here because of my skin color. I hadn’t known this was possible— to reject peopl efor being white. A hot wave passed throughmy body.
‘Righteous indignation’ is what Brother Gerald called it. Jesus had righteous indignation when he turned over the tables in the temple and drove out the thieving moneychangers. I wanted to march up there, flip acouple of tables over, and say, Excuse me, June Boatwright, but you don’t even know me.

"Righteous indignation" is an emotion that comes from mistreatment or unsult, and in context, the only type of anger that is not considered sinful.