Dating back to the feudal Middle Ages, Carnival Season is one of the various celebrations of the new Christian world, which replaced those, which we moderns label as pagan.
In particular, Carnival is thought to have replaced the Roman feast of Lupercalia, celebrated for centuries on February 15th of the Julian calendar, in honor of Lupercus, a Roman pastoral god associated with Faunus (satyr). Although Lupercus derives from jupus (wolf), the original meaning of the word, as it applies to Roman religion, has been obscured by time.
Carnival Season is sandwiched between Christmas Season and Lent. The Roman Catholic Church set Christmas Day on the 25th of December on the Gregorian Calendar. This approximates the winter solstice, the point at which the days start growing longer, ie the sun (light) is returning. Fixing this date, however, meant allowing the other Holy Days to float.
Easter is always on a Sunday. Easter can be any Sunday from March 23 to April 25. Its date is set to the Sunday that follows the first full moon after the spring equinox. Mardi Gras is always 47 days before this Sunday. (The 40 days of Lent plus 7 Sundays).
Carnival is from the Latin for “farewell to the flesh”. One is expected to bid earthly pleasures adieu in bacchanalian revelry, ie get it all out of your system before the privations of the Lenten Season. In medieval Europe, the landed nobles would ride through the countryside rewarding peasants with the fleshly pleasure of cakes (thought to be the origin of the King Cake), and coins (doubloons) and other trinkets (beads).
The beginning of Carnival Season is also fixed. It is January 6, the feast of the Epiphany or Little Christmas. In New Orleans, we call it Twelfth Night (of Christmas). Since the date of Fat Tuesday (Mardi Gras in French) varies, with Twelfth night being fixed, the length of Carnival Season varies from year to year. It is during this period that all of the Carnival balls and parades are held. These events are sponsored, designed, bankrolled, and executed totally by private clubs called “krewes”. A word invented in 19th century New Orleans. The various krewes also hold diverse fundraisers, and are usually involved in charitable work.
Since 1872 when Rex, the King of Carnival, selected them, the official colors of Mardi Gras have been purple, green, and gold. Probably chosen for their tonal harmony, they were given meaning 20 years later, again by Rex. The Rex Parade of 1892 was entitled “Symbolism of Colors” and assigned the following meanings to the three colors.