This is a great question. I love the way Toni Morrison creates this story without coming right out and saying which character is which race. I think that is the whole point that Toni is trying to make. She wants us to think about the issues that most women faced during this time in history.
Roberta and Twyla first meet each other at St. Bony's home for children. Most of the children there are orphaned, but these two girls have mothers. Their mothers are just not well enough to take care of them. We travel through the years with these two women. We see how both of them react to the issue of race and the tension that has filled the air. When the busing incident happens the lines are clearly drawn, but we still don't know which one is black and which one is white. We have to look at the issue again to try to come up with a solution. I think the most fascinating part of the story is Maggie, the mute young woman who worked at St. Bonny's. When she is pushed down in the orchard, Roberta and Twyla do nothing to help her—they even call her names. This goes to show the oppression of women. This oppression was even caused by other women. When Roberta accuses Twyla of kicking Maggie, the poor black girl, Twyla is furious. She is convinced that she never kicked her, but can't recall that she was black. This is what Toni Morrison is trying to get us to see: race shouldn't be the issue. She creates a story where we are kept in the dark about the race of the two women.
This is one of my favorite of Toni Morrison's short stories. She creates such complex characters. We can see Roberta and Twyla as both races, yet we are never told which one is which. We can also see ourselves in both of these women, which is the whole point. We need to overlook the issue of what color someone is and just look at the inside of a person. What a great concept.