The whole concept of the modern Santa Claus is commonly ascribed to a Coca Cola promotion. However, the idea was around long before then. See http://www.snopes.com/cokelore/santa.asp for details.
The modern red-and-white image of Santa derives from the poem The Night Before Christmas (see the annotation {16}), first published in 1822. Coca-Cola adopted him as an advertising symbol in the 1920s, and only since then have the colours become ‘fixed’. However, it is worth mentioning that St Nicholas was a 4th century bishop, who would have worn red and white robes.