My President Was Black, By Ta-Nehisi Coates - mentions a "brown-paper-bag test".
Brown Paper Bag Test (wikipedia entry) -
The Brown Paper Bag Test was a type of racial discrimination in the United States. A brown paper bag was used as a way to determine whether or not an individual could have certain privileges; only individuals with a skin color that is the same color or lighter than a brown paper bag were allowed. The test was used in the 20th century within many social institutions such as African-American sororities, fraternities, and churches.
What?? Even African-American organizations discriminated based on how dark a person's skin was?!
The Wikipedia "See Also" section for the above entry includes:
High yellow ...
...is a term used to describe persons classified as black according to the one-drop rule, despite having primarily white European ancestry. It is a color reference to the yellow undertone of some mixed-race people. ... It is reflected in such popular songs of the era as "The Yellow Rose of Texas".
What?! The Yellow Rose of Texas?! You mean the original song wasn't metaphorically comparing someone to a beautiful good-smelling yellow rose?
The Yellow Rose of Texas (song) ...
The song is written in the first person from the perspective of an African-American singer who refers to himself as a "darkey," longing to return to "a yellow girl," a term used to describe a light-skinned bi-racial woman born of African-American and white progenitors.