Why does Mary always wear light blue?
Well, she doesn’t.
“The older, classic and more representative color is dark blue,” according to the Rev. Johann Roten, S.M, director of the Marian Library-International Marian Research Institute at the University of Dayton. “Mary’s dark blue mantle, from about 500 A.D., is of Byzantine origin and is the color of an empress.”
Blue has stayed in vogue, but red has also become a prominent color for Mary as represented by artists since the 10th century. Blue calls to mind the color of the skies (which is not only limited to light blue), and red is the color of kings, Roten says. “However, there are a great variety of blues and other colors for Mary,” he says. “For example, Flemish painters prefer blue, while German painters have a preference for red.”
Regarding Mary represented with a red mantle:
As to the red mantle worn by Our Lady – this isn’t so rare either. Rogier van der Weyden, Hans Memling, Lucas Cranach, Geertgen tot sin Jans, Jan van Eyck but also sometimes Eastern iconography (mosaic, Chora monastery, 14th c) shows Mary cloaked in a red mantle. True, the classical tradition shows her with a red robe and a blue mantle as for example almost all Raphael Madonnas and those inspired by Raphael (Nazarenes). The red color in iconography points (early on) to nobility and elevated state, and conveys sometimes in northern Renaissance, in particular, an anticipation of suffering and passion, especially when related to the devotion of the heart as seems to be the case with the Christ image.
Marian artist Beverly Stoller works from her “Theotokos” art studio in Fairfield, Conn. She says a recent interest in iconography has led her to discover a new color scheme for Mary, based on historical representation in icons. Icons of Mary often show her wearing a greenish-blue inner garment with a red outer garment, Stoller says.