The white habit originates from a legendary dream in which Our Lady gave it to the Order.
Dominican friars, nuns and sisters are unique in wearing a white habit, as many other religious orders chose brown, grey or black for their clothing.
White is certainly not a practical color (considering how easily it can get stained), and was chosen by St. Dominic for its connection to a legendary dream.
According to Aleteia’s Fr. Patrick Briscoe in his book Saint Dominic’s Way of Life, published by Our Sunday Visitor, St. Dominic originally didn’t have a distinctive habit.
As a canon, Saint Dominic wore a white tunic with a surplice, looking much like an altar server clad all in white would look at Mass. The early friars adopted the same dress.
St. Dominic soon changed the newly established order’s habit after a miraculous vision.
This happened when a newly admitted member, St. Reginald of Orleans, became seriously ill.
St. Dominic prayed to God for a miraculous healing, and soon after St. Reginald regained his full health.
Afterwards, St. Reginald told St. Dominic a vision he witnessed, as narrated by the early 20th-century book Short Lives of the Dominican Saints.
And even whilst [St. Dominic] yet prayed, the Blessed Virgin Mary accompanied by the virgin martyrs Saint Cecilia and Saint Catharine, appeared to Master Reginald and extending her virginal hand, anointed his eyes, ears, nostrils, mouth, hands and feet, pronouncing certain words appropriate to each anointing. Then she showed him the habit of the Friars Preachers saying to him, “Behold the habit of thy Order,” and so she disappeared from his eyes and Reginald perceived that he was cured.
St. Dominic then announced they would exchange the white surplice for the white scapular given to them by Our Lady.
This story is commemorated each time a Dominican friar or nun receives the habit.
Receive the holy scapular of our Order, the most distinguished part of the Dominican habit, the maternal pledge from heaven of the love of the Blessed Virgin Mary towards us.
The white scapular then is a constant reminder of the Dominicans’ devotion to Our Lady, as well as to challenge them to a life of purity.