By our standards, if anyone had the right to wear white on their wedding day, it was the Blessed Virgin.
In the writings of Anne Catherine Emmerich, Our Lady's wedding dress is described thus:
"the beautiful sky-,blue wedding dress, ornamented with gold thread and strewn with embroidered roses, was made into a vestment for the Holy Sacrifice for the Bethsaida church in Jerusalem. There are relics of it in Rome still...Mary wore it only for her wedding and never again."
pg 383, The Life of the Blessed Virgin Mary, from the visions of Ven. Anne Catherine Emmerich TAN
Wouldn't it be wonderful if traditional brides wore blue in imitation of Our Blessed Mother?