The Roman Missal and the Roman Rite Liturgy of the Hours naturally includes references to Mary's immaculate conception in the feast of the Immaculate Conception. An example is the antiphon that begins: "Tota pulchra es, Maria, et macula originalis non est in te" (You are all beautiful, Mary, and the original stain [of sin] is not in you. Your clothing is white as snow, and your face is like the sun. You are all beautiful, Mary, and the original stain [of sin] is not in you. You are the glory of Jerusalem, you are the joy of Israel, you give honour to our people. You are all beautiful, Mary.) On the basis of the original Gregorian chant music, polyphonic settings have been composed by Anton Bruckner, Pablo Casals, Maurice Duruflé, Grzegorz Gerwazy Gorczycki, no:Ola Gjeilo, José Maurício Nunes Garcia, and Nikolaus Schapfl,

What color garment is used in traditional chants to represent the purity of Mary's conception ?