Revelation 6:2
"And I saw, and behold a white horse: and he that sat on him had a bow; and a crown was given unto him: and he went forth conquering, and to conquer."
Cross References (ranked by relevance)
Zechariah 1:8
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.
Revelation 14:14
And I looked, and behold a white cloud, and upon the cloud one sat like unto the Son of man, having on his head a golden crown, and in his hand a sharp sickle.
Revelation 3:21
To him that overcometh will I grant to sit with me in my throne, even as I also overcame, and am set down with my Father in his throne.