I noticed that my link in one of older post was wrong: http://www.navweaps.com/index_tech/tech-100.htm
For USA:
In the mid-1920's, both the Naval Powder Factory at Indian Head and the DuPont Co. developed flashless powders. The Powder Factory had also obtained good results by mixing flash-reducing chemicals with the conventional powder charge. Flashlessness, however, was gained only by an increase in the amount of smoke, which was unacceptable to the fleet as it interfered with searchlight illumination and fire control. By 1928, BuOrd had stopped work on flash suppression. With the advent of radar in World War II, smoke became less objectionable and the fleet was willing to accept considerably more smoke in order to obtain a significant reduction in flash. At the time the request for flashless powder was received, BuOrd had already accumulated large inventories of smokeless powder. In order to prevent this material from being discarded, some means of converting it into acceptable flashless charges had to be found.
From Regiamarina link in my older post:
The moon had just set; reducing the general illumination and depriving Ajax of the backlight that made the Italian ships, stand out. Not equipped with flashless gunpowder, the repeated flashes from Ajax's guns blinded her crew with every salvo. Nonetheless, at 0230 Ajax's gunners finally hit the elusive Artigliere and hit her hard, killing the flotilla commander, Captain Margottini and bringing her to a halt.
