St. Valentine's Day has become a day where everyone wears red, hanging-up decorations of red hearts, or simply making red a primary color in their house and office.
While the color red is clearly being used in connection to the red hearts that are everywhere, in truth the color has a much deeper meaning.
Red for martyrdom and burning love
The Church has chosen red as the primary color for feasts dedicated to martyrdom and sacrifice, as the Catholic Encyclopedia explains.
This is why red is used both on feasts of martyrs, as well as other feasts such as Pentecost. Red for Pentecost can be seen in reference to the flames of fire that came down upon the apostles, as well as the fire of “burning charity” that arose in them after that day.
It is fitting, then, that Valentine's Day highlights the color red, for it reminds us of the supreme sacrifice of St. Valentine and the profound love he had for God and neighbor.