The traditional Catholic Advent wreath has four candles – 3 purple, and 1 rose-colored or pink. The four candles represent the four Sundays of Advent. On the first, second, and fourth Sundays of Advent, we light a purple candle, and on the third Sunday of Advent, we light the rose-colored candle.
For reasons that are unknown to me, in Honduras, people have a different kind of Advent wreath that has four different colors of candles; white, green, blue, and rose.
The image above shows such a traditional Advent wreath in Casa Mata, one of the buildings that is part of Catholic University of Honduras in Tegucigalpa.