Billy Idol had it all wrong about the connotations of brides wearing white at weddings. Although he was trying to insinuate that his "little sister" in "White Wedding" shouldn't have been wearing white to her nuptials since she had -- gasp! -- had sex, the tradition of brides wearing white actually has nothing to do with virginity.
On February 10, 1840, Queen Victoria married her cousin Albert and established a lasting bridal custom by wearing an off-white, silk-satin gown. Electing to wear the creamy-hued confection was a radical decision at the time, sartorially-speaking, because silver was go-to color for royal wedding dresses, and brides in blue and yellow were also popular -- but certainly not white.
And as Hanne Blank notes, the purity denoted by the white dress wasn't so much referencing sexuality but rather cleanliness and luxury, as it would be difficult to keep clean and impractical to wear outside of an occasion like a wedding. Indeed, an 1850 wedding dress bill cited in "Courtship and Marriage in Victorian England" opines: "Of what use is the costly white silk bridal dress, which in all human probability will never in its original state be worn again? It will, of course, be laid up carefully, and looked at occasionally with tender sentimental interest; but by-and-by, in a year or two, it will seem old-fashioned, and most probably be picked to pieces and dyed some serviceable colour."
For the non-royal brides at the time, it was more common to wear one's best dress she already owned or more versatile dresses in shades of brown, blue or gray. Today's practice of buying a one-time wedding gown would've been considered an extravagance only suited to wealthy types like Queen Victoria. But as bridal culture began its wedding march toward today's average $26,000 price tag, the dresses quickly became whitewashed thanks to Queen Victoria's stunning example. In 1865, for instance, "The Etiquette of Courtship and Matrimony" stated "A bride's costume should be white." Likewise, Godey's Lady's Book, which was one of the most popular and influential magazines in the United States at the time, around the same time had declared: "Custom has decided, from the earliest ages, that white is the most fitting hue, whatever may be the material. It is an emblem of the purity and innocence of girlhood, and the unsullied heart she now yields to the chosen one."
In which case, the virginal connotations for white wedding gowns is pure magazine editorial fiction. If it's, in fact, an "emblem" of anything it's of a Queen who broke convention to make a political statement, which is quite an improvement when you think about it.