The two colors that most people think of when they think of Christmas are red and green.

Red is the color of Santa's suit and and Rudolph's nose. Green is the color of the Christmas tree and of mistletoe and of holly and ivy. And therein lie a few clues as to the origin of these two colors as the "official" colors of the holiday.

Christmas as it is celebrated today, with all of the modern trimmings and trappings, was largely shaped in the 19th Century. The origins of the celebration of the holiday go back further, of course.

For a great many years, evergreen plants have been celebrated for their growth even in the dead of winter. Evergreen trees are common choices for Christmas trees. Other evergreen plants include holly and ivy. The holly plant is both green and red, with the berries being red and the leaves being green.

In Roman times, people hung holly wreaths on their doors and walls in what we now call December, in the middle of the Northern Hemisphere winter. The pre-Christian Romans celebrated a winter solstice festival called Saturnalia; associated with that festival were the holly wreaths, their evergreen nature celebrating the rebirth of the harvest as the days got warmer and moved toward spring and summer. The Romans also exchanged holly, ivy, and mistletoe branches as (they hoped) items that would bring good luck. The idea of using holly to celebrate the winter solstice was also popular in more recent times, with Celtic peoples.

In terms of red, it is the color of the holly berry and the poinsettia, a red shrub that blooms in winter, but it is also the color of Santa Claus's suit, and that is the courtesy of an advertising campaign by Coca-Cola. Descriptions of Santa varied through the years. The first hint of the modern conception of Santa was in The Night Before Christmas, which appeared in the early 19th Century. Santa was described as being not at all the thin man wearing blue or even green robes, as he had been thought of, in the stories of Saint Nicholas that dated hundreds of years before, but of a large man.

The next step in Santa's evolution came in the form of a set of drawings by an ad exec named Haddon Sundblom, who in 1931 came up with the idea that Santa was an overweight man who wore red robes. Not coincidentally, red was also the color of the Coca-Cola logo and the color often found on cans of the soft drink and in other ads for the product.

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