White horse
From ReformedWiki.org, the wiki for Reformed Christianity
There are many references to "White horses" in the Bible, specifically being ridden by the first horseman of the apocalypse in the Book of Revelation as well as being ridden by Jesus later in chapter 19. They are also referenced in the Book of Zechariah in the first vision and in the vision of the four chariots.
They are a common symbol of the divinity of Jesus as God the Son.
