Until the Virgin Mary Made Her Appearance

According historian and symbologist Michel Pastoureau, author of the book Blue: The History of a Color, blue was one of the later colors to be adopted in the ancient world (with reds, blacks, and browns appearing in cave paintings).

In Ancient Rome, it was seen as the color of the working class, worn by the those lower on the social ladder, while the wealthy wore white, black, and red. Pastoureau says that the color was seen as so far out of the mainstream that it was associated with barbarians and used to frighten enemies.

That low opinion of the color blue changed significantly when it became the color of the cloak of Virgin Mary as she developed in the 12th century. As the image become more widespread, the color was seen as far more respectable and worthy of reverence, spreading to other religious imagery.