Why is rose used during Advent in the Advent wreath and vestments?

Answer

Advent is a time of penance, and so the ordinary liturgical color for Advent is violet. On the third Sunday of Advent, which is also calledGaudete (Latin: “Rejoice”) Sunday, we recognize the joyful anticipation of the season that will culminate in the birth of Christ on Christmas by changing the liturgical color to rose. Rose is a “brightening” of the ordinary violet and thus symbolizes joy.