Recitatif and Morrison's cues

Hey everyone!
After Monday’s discussion on Toni Morrison’s “Recitatif” I started thinking a lot more about the social and racial cues that may hint which character is black and which is white. I found it interesting to see which people were picked up on what clues. One clue I was hoping to discuss but we ran out of time was name selection. I find Morrison’s choice for the names of his characters very interesting: Twyla and Roberta. As soon as I started reading this text, I used the names as racial indicators. At first, I thought Twyla was the black girl and Roberta was the white girl and this assumption was solely based on their names. When I realized that I was making that assumption, I immediately thought of the Trepannier reading and was a little shocked. Was my assumption somewhat racist? I didn’t know. This worried me. Interestingly, I asked five of my friends to read both names and identify one as black and one as white. Surprisingly, three (males) responded that Roberta was black and Twyla was white whereas only two (males) responded that Twyla was black and Roberta was white. My question for everyone was whether or not the names Morrison chose for his characters sparked a response in any of you? Just by reading the names, what did you guys think? Do you think Morrison did this on purpose? If so, why?