To make hat: Mix green fondant from Primary Colors Multi Pack with 1/2 teaspoon of Gum-Tex, roll out 1/8 in. thick. For brim, cut a 5 in. circle with a 2 1/4 in. circle cut out at center. Let dry on cornstarch-dusted board. Cut a 3 in. circle for top of hat and turn over.
For hat sides, cut a 10 x 2 in. strip; wrap around top of hat, attach with
thinned fondant adhesive. Support inside with double-thick strip of freezer paper, facing shiny side toward fondant. Let dry overnight. Remove freezer paper and attach hat to brim with thinned fondant adhesive.
For hatband, roll out red fondant 1/8 in. thick; cut a 10 x 1/2 in. strip; attach with damp brush. Let dry overnight on cornstarch-dusted board.