At what point did Janie discover she was black?

Janie discovered she was black when she saw herself in a picture with the Washburn children.

“So when we looked at de picture and everybody got pointed out there wasn’t nobody left except a real dark little girl with long hair standing by Eleanor. Dat’s where Ah wuz s’posed to be, but Ah couldn’t recognize dat dark chile as me. So Ah ast, ‘where is me? Ah don’t see me.’

“Everybody laughed, even Mr. Washburn. Miss Nellie, de Mama of de chillun who come back home after her husband dead, she pointed to de dark one and said, ‘Dat’s you, Alphabet, don’t you know yo’ ownself?’

“Dey all useter call me Alphabet ’cause so many people had done named me different names. Ah looked at de picture a long time and seen it was mah dress and mah hair so Ah said: “ ‘Aw, aw! Ah’m colored!’