Mardi gras has three official colors:
le violet purple (justice)
l'or gold (power)
le vert green (faith)
Mardi gras takes place 46 days before Easter (le Pâques) - that is, sometime between 3 February and 9 March. Mardi gras is the day before Lent (le carême), which begins on Ash Wednesday (le mercredi des Cendres). The most famous Mardi gras celebration is held in New Orleans (la Nouvelle-Orléans), but many cities in Europe and the Americas also put on spectacular events.
Mardi gras' slogan is "Let the good times roll," which is translated literally into French as Laissez les bons temps rouler.