Zechariah 6:2
"In the first chariot were red horses; and in the second chariot black horses;"
Cross References (ranked by relevance)
I saw by night, and behold a man riding upon a red horse, and he stood among the myrtle trees that were in the bottom; and behind him were there red horses, speckled, and white.
And there appeared another wonder in heaven; and behold a great red dragon, having seven heads and ten horns, and seven crowns upon his heads.
So he carried me away in the spirit into the wilderness: and I saw a woman sit upon a scarlet coloured beast, full of names of blasphemy, having seven heads and ten horns.
The black horses which are therein go forth into the north country; and the white go forth after them; and the grisled go forth toward the south country.