What do we know about the members of the Blue Vein Society?

The Blue Vein Society chooses its member based up the color of their skin. Racial bias, stemming from skin color, was the basis of the Blue Vein Society. Black people whose skin was light enough to see the color of their veins beneath it are allowed to join the society; those with darker skin are rejected. The story's main character, Mr. Ryder, is one of the leaders in the society. He places extreme importance on the color of his skin, and he believes that over time, it will be important to produce children with lighter skin.