PURPOSE: To enable to have mottled smoke of multi-colors fumed by operating a control switch for switching valves connected with respective fuming oil tanks with different pigments mixed, and disposed at plural passages comprising a smoke nozzle opening into engine exhaust.

CONSTITUTION: When a valve 5A is opened and a valve 5B is closed through a controller 10 by means of a control switch 8, the fuming oil 2A in a fuming oil tank 1A is injected into the exhaust pipe 13 of a jet engine 4 from a smoke nozzle 9 through a passage 11A, the valve 5A and a smoke nozzle tube 9 by means of a pump 3A. The fuming oil 2A is carburetted by exhaust air 6, and smoke 12 of the colors corresponding to the pigments mixed in the fuming oil 2A is generated. When the valves 5A, 5B are switched after the appropriate time elapsed through the controller 10 reoperating the control switch 8, the fuming oil 2B in the fuming oil tank 1B is injected into the exhaust pipe 13, and the smoke 12 of different colors is generated.