Perceptions of Color

You raised the critical question, thus you owe us an answer. When is a person “black” and when is he or she “white”?

For example, is a person black whose great-great-great-great-great-great grandmother was born in Africa but whose parents and grandparents since then were white?

What is the difference between what you call a “very light skinned” black person and a “very dark skinned” white person? “We always know,” says one of the blacks you quoted. How?

PATRICK GROFF, San Diego