Personalized Keep Calm Mardi Gras Youth Long Sleeve T-Shirt. Mardi Gras Youth Long Sleeve T-Shirt - Black with green, purple and yellow fleur de lis says KEEP CALM AND MARDI GRAS. Distressed finish. Perfect for Fat Tuesday parades and celebrations. youth long sleeve t-shirt. Shoulder-to-shoulder taping. Youth: S(6/8), M(10/12), L(14/16), XL(18/20)