From Aleteir 3/15/2020 For the people of Israel blue brings to mind the following of God’s Commandments, as opposed to a person’s selfish will.
This was perfectly lived out by the Blessed Mother who said, “Behold, I am the handmaid of the Lord; let it be to me according to your word” (Luke 1:38). She was the faithful “Daughter of Zion” who fulfilled the call of obedience that God had asked of the Israelites.
Additionally, Numbers indicated that “the Levites are to ‘spread over [the Ark of the Covenant] a cloth all of blue’ (4:6). And further: ‘And over the table of the bread of the Presence they shall spread a cloth of blue’ (4:7).”
Mary is traditionally referred to as the new Ark of the Covenant, as she held within herself the Divine Presence of God. Blue in iconography represents transcendence, mystery, and the divine. It is the color of the sky and as a result is viewed as a heavenly color. Jesus is typically depicted in icons with a blue outer garment and a red inner garment, symbolizing how divinity wraps his humanity.
Mary on the other hand is seen with a red outer garment and a blue inner garment, representing how she carried divinity (Jesus) within her humanity.
When Mary appeared to Saint Juan Diego, she wore a blue-green mantel. According to the Knights of Columbus, “the star-speckled green-blue mantle symbolizes the heavens. In addition, the mantle’s color indicates her royalty, since only the native emperors could wear cloaks of that color.”