Because it is so old, this is one of the Marian doctrines that Islam shares with the Catholic Church, though of course the theological details are very different. ‘in a famous Hadith attributed to the Prophet, it is affirmed that: “Every child is touched by the devil as soon as he is born and this contact makes him cry. Excepted are Mary and her Son”. From this Hadith and from verses 35-37 of Sura III, Moslem commentators have deduced and affirmed the principle of Mary’s original purity.’ (Giancarlo Finazzo. L’Osservatore Romano, 13 April 1978). The full text of the article is here.

  The doctrine of the Immaculate Conception was almost universally believed over the centuries but was only formally defined as a doctrine of the Church by Pope Pius IX in 1854.

  In the earliest centuries all vestments were white – the white of baptismal purity and of the robes worn by the armies of the redeemed in the Apocalypse, washed white in the blood of the Lamb. As the Church grew secure enough to be able to plan her liturgy, she began to use colour so that our sense of sight could deepen our experience of the mysteries of salvation, just as incense recruits our sense of smell and music that of hearing. Over the centuries various schemes of colour for feasts and seasons were worked out, and it is only as late as the 19th century that they were harmonized into their present form.