The four horsemen are; Conquest (white), War (red), Famine (black), and Death (pale)
Excerpt from Revelation 6:1-2, on the White Horsemen:
I watched as the Lamb opened the first of the seven seals. Then I heard one of the four living creatures say in a voice like thunder, “Come and see!” I looked, and there before me was a white horse! Its rider held a bow, and he was given a crown, and he rode out as a conqueror bent on conquest.
Although the first horsemen is referenced as Conquest, other interpretations call it Pestilence which would mean the bringer of disease and infection.
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