Hello everyone.
Yes, this item was and still is (although in a modified version) part of the Bundeswehr’s inventory. The smoke colour is orange (as rigby has already mentioned).
As far as I can recall, this smoke grenade was used in particular to mark landing zones for helicopters and to indicate the wind direction to the crew. The brown cap should be twist-off. Beneath it is the friction wire igniter. The pull cord is connected to the brown protective cap. The stencilled ‘C’ stands for ‘Colour’ and is printed in the colour ‘rotorange – RAL 2001’. The igniter has a pyrotechnic delay of approximately 2 seconds. The smoke charge, based on potassium chlorate, burns out in approximately 105 seconds.
However, I believe that the brown protective cap of your example may not be original. The original brown protective cap on the Bundeswehr version should only have four large ribs and is smaller in diameter, but slightly taller.
As far as I recall, Comet reproduced military pyrotechnics for the civilian market, making minor alterations in the process. Perhaps your example is one of such versions. I might be able to find out more about it when I’m back on duty on Thursday.
Hope that helps for now.
Best regards from Germany,
URG-86-collector