Out of the Inkwell is a 1938 Max Fleischer/Betty Boop live-action and animated short film.
A live-action black janitor, played by Oscar Polk, best known for his portrayal as the servant "Pork" in the 1939 film Gone with the Wind, studies hypnotism from a book while cleaning Max Fleischer's desk at the Fleischer studio.
He manages to conjure Max's pen into drawing Betty Boop.
Fraught with racial innuendo, one of her tricks includes turning the black man white for a split-second, after which he begins cleaning in overdrive.
There is a colored porter, who picks up hypnotism from a book lying on a cartoonist's desk.