Third Sunday of Advent - (this is abstracted from Jimmy Atkins blog = Catholic Answers)
The color violet or purple is used in Advent.
In many places, there is a notable exception for the Third Sunday of Advent, known as Gaudete Sunday: Gaudete is the Latin word for “Rejoice,”
which is the first word of the introit of the Mass for this day.
The color rose may be used, where it is the practice, on Gaudete Sunday (Third Sunday of Advent)