You are confused if you think those women are anything but white
half black is black
1/4 black is not black
1/8 black is essentially white
New Orleans had Quadroon and Octoroon balls. Where they had quadroon and octoroon women who were presented to rich Frenchmen (Creole) who many times had their own white families.
The Quadroon and Octoroon men often times were excluded from said balls. They either were educated in Franch, or waited their turn and dealt with the women after the Frenchmen were done with them. Often times taking care of the kids the Frenchmen left behind.
Many of the women were very pretty. There are pics if you google.
a good book (fictional) on said topic, Ann Rice's The Feast of All Saints (and the show).