Wartime colour photos show that two colours were used for the practice heads for torpedoes, red and yellow. Does anyone know what the two colours indicated in the RAF and FAA? A search of the internet proved inconclusive.

My suspicion is that blowing heads were one colour and collapsible heads were another but that is just a suspicion. I am not sure if ship launched torpedoes used the same colours but assume so as they were supposed to be interchangeable. Live torpedoes were not coloured as far as I know.