I took a moment to research about vestments and colors in the liturgical life of the Church.  Today, I will explain the chasuble http://www.newadvent.org/cathen/03639a.htm and its evolution;  then, I will explain why the color rose is used in the liturgy of the Catholic Church.

The evolution of the name of what is now today known as chasuble is very interesting.  Cloaks and robes were worn by religious and political figures during the time of Jesus.  In the Roman Empire vestments similar to chasubles were worn by civilians as well.  In the bible, we can find numerous references about cloaks and robes.   Even St. Paul refers to certain vestment: a “cloke”.  “The cloak that I left at Troas with Carpus, when you come, bring with you, and the books, but especially the parchments”. 2 Tim 4,13. According to Ellicott Commentary of the Bible “Paul is requesting Timothy, on his way, to bring with him a thick cloak, or mantle, which St. Paul had left with a certain Carpus at Troas. Probably, when he left it, it was summer, and he was disinclined to burden himself in his hurried journey with any superfluous things. Winter was now coming on, and the poor aged prisoner in the cold damp prison, with few friends and scant resources, remembered and wished for his cloak”.

In the second century, vestments for liturgical ceremonies were called “paenula“ or a wide round covering with a hole in the middle for the head. In the fourth century, this vestment was called “planeta”.  During the seventh century was finally called chasuble or “casula” meaning a little tent, small house or a little room.  The chusable resembled a tent since the wearer’s head were covered by a hood in a conical shape. “There is not liturgical law prescribing the decoration of the chasuble. It may be left unadorned as was practically the general case until the twelfth century”  (Lasage, Vestments and Church Furniture, 123). http://modernmedievalism.blogspot.com/2013/08/a-look-into-medieval-parish-churchs.html

The Color Rose:  Gaudete Sunday/Laetare Sunday 

The Third Sunday of Advent is also called Gaudete Sunday which means joyful Sunday.  Certainly, we are joyful because our Savior is about to come to the world to lift up humanity and save us from the power of darkness.  The color Rose means joy and happiness.  Salvation is coming to illumine the world; the use of rose helps to tie into this spirit of gladness and joyfulness which the Church wishes to present to us.

The Liturgy of the Word complements this joyful Sunday and today’s psalm tells us about the same joy that the most blessed Virgin Mary is proclaiming:

My soul rejoices in my God.  Is 61,10
My soul proclaims the greatness of the Lord;
my spirit rejoices in God my Savior,
for he has looked upon his lowly servant.
From this day all generations will call me blessed:
R. My soul rejoices in my God.    LK 1:46-48, 49-50, 53-54

In the same way, the fourth Sunday of Lent: Laetere Sunday, (the word laetere comes from the Latin laetare, the singular imperative of laetari: “to rejoice”) tells us about rejoicing in the Lord who is going to resurrect on Easter Sunday. The psalm of the day also emphasizes this joy by saying:

“Rejoice, O Jerusalem: and come together all you that love her: rejoice with joy, you that have been in sorrow: that you may exult and be filled from the breasts of your consolation. Psalm: I rejoiced when they said to me: ‘we shall go into God’s House!'”

https://aleteia.org/2017/03/24/why-is-my-priest-wearing-pink/

So, next time that you see your priest wearing rose, you will remember to be joyful and show him that a golden smile or a golden rose…

https://www.fisheaters.com/customslent7.html