Why do we use Sarum Blue for Advent? Before the Protestant Reformation and the publication of the original 1549 Book of Common Prayer, the Roman rite was obviously the only rite used in the Church throughout the world. However, as early as the 11th century, St. Osmund, Bishop of Salisbury, had established a variation of the rite for use in Salisbury Cathedral and in that diocese. In this Sarum Rite ("Sarum" being the Latin word for "Salisbury"), blue was used for the season of Advent. Blue is the color historically associated with the Virgin Mary (thus often called "Marian blue" as well as "Sarum blue"), and blue symbolized the night sky or darkness, an image present in many of the scriptures used in Advent season.
The Advent lectionary readings also highlight the expectancy of Mary and our preparation for the Christ Child. Mostly notable is the Sunday on which the Magnificat (Mary’s Song of Praise) is the appointed Gospel, which is usually Advent III or Advent IV depending upon the lectionary year. Therefore, in the post-Reformation Anglican Church, and because of its usage in the Sarum Rite, Sarum blue is the most appropriate color for Episcopal usage. Contemporary liturgists and especially our 1979 Book of Common Prayer lift up this preparatory nature of Advent instead of the penitential nature most associated with Lent. While purple emphasizes the penitence as appropriate for the Lenten season, Sarum blue emphasizes our expectation in the Advent season as we await, with Mary, the coming of the Christ Child.