Black humour (so named by Huysmans) is the purest, most death-related and most magnificently outrageous form of humour. But it is not the only one. For the first time, other colours are attributed to humourists here, with definitions and examples: yellow as self-mockery, green as false naivety, grey as the world seen by a depressive, red as revolt turned into laughter, purple as blasphemy in a cardinal's robe, blue as delirium disguised as everyday banality, chameleoresque as parody, white, finally, as comical euphemism, absurd phrases or suicidal dandy pirouettes. This rainbow is caught between two lights: that of a general theory of humour, which starts from the achievements of Bergson or Freud and a reflection on certain figures of speech, and that of numerous examples mainly borrowed from twentieth-century French literature, from Jarry to Vialatte and from Dada to Dubillard.