Final answer:
Blue vein societies were exclusive groups in the African-American community that signified social stratification based on skin color, where membership was partly determined by the visibility of blue veins through lighter skin.
Step-by-step explanation:
Blue vein societies could best be described as groups that have historically emphasized the social stratification based on skin color within the African-American community, particularly during the post-Civil War era in the United States. These societies were exclusive social organizations that some lighter-skinned African-Americans created, with membership often based on skin color being light enough that the blue veins were visible, a practice that implied an underlying colorism within these communities. The term does not directly relate to traditional anthropological or sociological classifications of societies like band, tribal, or state societies; nor does it align with the definitions of Blue Zones, tribal societies, or bicommunal societies provided in the reference information.