“Customarily the Advent Wreath is constructed of a circle of evergreen branches into which are inserted four candles. According to tradition, three of the candles are violet and the fourth is rose. However, four violet or white candles may also be used” (Book of Blessings 1510).
The purple candles in particular symbolize the prayer, penance, and preparatory sacrifices and goods works undertaken at this time. The rose candle is lit on the third Sunday, when the priest also wears rose vestments at Mass for this color anticipates and symbolizes the Christmas joy announced in the first word of the Entrance Antiphon: “Rejoice” (Latin, Gaudete); for this reason the Third Sunday is also called Gaudete Sunday. It is the Sunday of rejoicing, because the faithful have arrived at the midpoint of Advent, when their preparation is now half over and they are close to Christmas.
The progressive lighting of the candles symbolizes the expectation and hope surrounding our Lord’s first coming into the world and the anticipation of his second coming to judge the living and the dead.