In stand up, "working blue" refers to using crude humor, profanity, and discussing sex and generally taboo topics.
The term is theorized to originate from censorship in early 20th-century Vaudeville, where theater managers would take note of offensive lines using blue ink or send warnings in blue envelopes.
His material is usually working blue, so I won't invite the whole family to the show.
Working blue is when you have a lot of work to do, but you keep going even when you feel tired or stressed. It means staying determined and finding a littlemotivation in getting things done.
After a long week, I’m finally in my working blue, finishing my projects and feeling good about what I’m doing.