Revelation 9:16-18

16The number of the troops of cavalry was twice ten thousand times ten thousand (two hundred million); I heard the number of them.

17And this is how I saw the horses and their riders in my vision: the riders had breastplates [the color] of fire and of hyacinth (sapphire blue) and of brimstone (yellow); and the heads of the horses looked like the heads of lions; and from out of their mouths came fire and smoke and brimstone (burning sulfur).

18A third of mankind was killed by these three plagues—by the fire and the smoke and the brimstone that came from the mouths of the horses.