Why don’t we have a pink candle in the Advent wreath? Why would we use a pink candle in the Advent wreath? Ken Collins (no relation) has a good explanation in his Worship Glossary.
“Rose [Optional] Rose (that is, a shade of pink) was sometimes used on the third Sunday in Advent, to signify joy.”
“The use of the color rose has a strange origin. Long ago, the pope had the custom of giving someone a rose on the fourth Sunday in Lent. This led the Roman Catholic clergy to wear rose-colored vestments on that Sunday. The effect was to give some relief the solemnity of Lent, so this was a very popular custom. Originally—before shopping malls—Advent was a solemn fast in preparation for Christmas, so the custom was extended to the third Sunday in Advent to liven it up a little bit, too. Somewhere in there the third candle of the Advent wreath turned pink. Meanwhile, Advent is no longer solemn and the pope no longer has the custom of giving out roses. It is kind of odd to think that a Methodist would put a pink candle in a Lutheran Advent wreath because the pope used to have the custom of giving out roses, but sometimes we’re a little more ecumenical than we realize!”
“In the Catholic Church, rose is an alternative color for the fourth Sunday in Lent (Laetare Sunday) and the third Sunday of Advent (Gaudete Sunday).”Copyright ©1995-2007 by the Rev. Kenneth W. Collins. Reprinted with permission.
And from the United Methodist Book of Worship (pretty much the final word on all things liturgical in the United Methodist Church):
“Some traditions us the color rose on the Third Sunday of Advent and for this reason use three purple candles and one rose candle. United Methodists, however, encourage purple for the whole season of Advent and therefore us four purple candles.”
For the above reasons we use four purple candles in the advent wreath.