'Fiery red' in the Bible

And 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).

Then another sign [of warning] was seen in heaven: behold, a great fiery red dragon (Satan) with seven heads and ten horns, and on his heads were seven royal crowns (diadems).