I like my coffee so black It harvests it's own sugar
I don't understand why you would say something like that
It's just a joke about the color of their skin. What is so bad about it?
It's harmful to make jokes about people's skin color, or to excuse people who make such jokes.  People of color have to face discrimination on a daily basis, and perpetuating these attitudes only makes the problem worse.  Besides, it's not right to judge people for their ancestors being slaves, since they hardly had a choice in the matter, did they?