NWT Coach Green Enamel Heart And Signature Stud Earrings Set- 2 Pairs. This stud earring set features the Coach Signature “C” made of plated brass and accented with a sparkling crystal, and a bright green enamel heart accented by the Coach Signature “C”. Both pairs have hypoallergenic titanium posts and butterfly closures. The shine and colors are perfect for the holidays!