Here's a wikipedia definition of black humor for you.  It has nothing to do with racism. 

 "Black comedy, also known as black humor or dark comedy, is a sub-genre of comedy and satire where topics and events that are usually treated seriously are treated in a satirical manner while still being portrayed as the negative events that they are. Typical targets are death, (mass) murder, suicide, blackmail, (domestic) violence, disease, insanity, handicaps, environmental disasters, famine, fear, child pornography/abuse, drug abuse, rape, castration, war, terrorism, racism, sexism, homophobia, bestiality and line-cutting. "  Please note that "insanity (mental illness) is one of the topics included.  

I spent 28 years teaching and counseling dysfunctinal adolescents and don't really need your condescensing comments relating to working with disturbed kids. 

 Additionally, if you intend to lecture me on "black humor", please first become familiar with its definition.