Via J-Walk Blog I saw this site with ads for Christmas by Thomas Nast. The site in Portuguese says that Nasty was the first to design Santa Claus with that colours and not Coca-Cola, and you can see on the coloured ads.
Thomas Nast was a celebrity. In 1873, following his successful campaign against New York City’s Tweed Ring, he was billed as “The Prince of Caricaturists” for a lecture tour that lasted seven months. Nast used his Harper’s Weekly cartoons to crusade against New York City’s political boss William Magear Tweed, and he devised the Tammany tiger for this crusade. He popularized the elephant to symbolize the Republican Party and the donkey as the symbol for the Democratic Party, and created the “modern” image of Santa Claus.