All Church vesture achieves its effect by its cut, color, and texture. Color appeals most quickly to the emotions, and the proper use of it can help the priest and people to feel the mood and spirit of a particular feast day. Colors of the spectrum may be associated with two moods: the warm, active, and exciting qualities of red and the cool, passive, and calming qualities of blue, violet and green. Because of these associations, it is not surprising that a color sequence proper to particular feasts of the Church year became the subject of ecclesiastical legislation.
The first such legislation known is that of the 12th-century crusaders written for their Church at Jerusalem. Innocent III (1198–1216) prescribed five colors for liturgical use in the Roman Rite: white, red, green, black, and violet (De Sacro Altaris Mysterio 1.65). Although the directive is precise about what colors are to be used, it leaves the choice of shades of these colors to the vestment maker. Innocent III's color scheme forms the basis for contemporary practice. White is worn on Sundays in Eastertide, on solemnities of Our Lord and the Blessed Virgin Mary, and for funeral masses; red is used for Pentecost and the feasts of apostles and martyrs; violet for Advent and Lent; and green for Sundays in ordinary time. From the 13th century onward, the practice of wearing rose-colored vestments on the 3rd Sunday of Advent (Gaudete Sunday) and the 4th Sunday of Lent (Laetare Sunday) caught on.
Bibliography: w. h. hope and e. g. atchley, Liturgical Colors (Society for Promoting Christian Knowledge; London 1918).