Symbolism of Advent wreath elements

Many elements of the Advent wreath have symbolism, sometimes more than one meaning, sometimes contradictory meaning. 

Untitled Document
evergreen branches

hope; eternal/new life in Christ

circular shape no beginning, no end; eternity; God
candles period of waiting four Sundays of Advent (which is itself symbolic of the four centuries of waiting from time of Malachi to time of Christ;) Christ is seen as light of the world
increasing accumulation of light gradual revelation to Israel of the coming of Christ
blue candles traditional color of Mary; night sky as it lightens toward dawn; hope the Messiah brings to the world; penitent color other than purple used in Lent
purple candles royalty/soveriegnity of Christ, "Prince of Peace;" penitence
pink candle joy (celebratory rather than penitent readings on this day)
white candle(s) Christ; daylight; celebration; Christmas season
first candle hope
second candle peace
third candle joy
fourth candle love