What's the difference between gray humor and black humor?

Black humor is different from ordinary humor. Its absurdity, cynicism and cynicism contain heaviness and anguish, tears and pain, melancholy and cruelty, so its wry smile contains tears and even anger. Later, people usually used the word "black humor" in this sense.

What is humor and what is gray humor? The dictionary is full of related entries, which are too dry to understand. An example from the news is very telling.

It is said that in Shanghai, there was a man who was extremely tired of the world and jumped into Suzhou River with the determination to die. When the police arrived, they tried to convince me, but it was useless. I must die. After smoking a cigarette, the dead man changed his mind and climbed up by himself! The person next to him asked, Hey, why are you still alive? Answer: The river stinks unbearable. I really want to die!

This is gray humor. What a joke: you are ready to die, and you are still afraid of the smelly water? But if this matter is put in the environmental protection bureau, it will not be a joke: it can only show that the pollution is too serious!