Oops, forgot Advent 2. Oh well. Due to calendar there is no Advent 4 this year.
The Altar paraments for Advent are purple. Why? Purple is the color of royalty. The King has come to us. Purple is also the color of repentance. Rightly so.
700 years before Christ the prophet Micah wrote under the inspiration of the Holy Spirit (yes, it became true):
Micah 5:2-3
“But you, Bethlehem Ephrathah,
though you are small among the clans[b] of Judah,
out of you will come for me
one who will be ruler over Israel,
whose origins are from of old,
from ancient times."
v5 "He will be their peace."
Predictive prophecy strikes again.