 It is not designated the "AN-M18" but "M1The violet-colored smoke grenade was used in-theater because of its vivid color; previously it was only used in the United States for training.Its smoke was more toxic than the other color mixtures and was removed from the inventory after the end of the Cold War in the 1990s.The green-colored smoke grenade was still used in Southeast Asia because the jungle undergrowth was a different color and would still contrast with it.