In small bowl, mix frosting and food colour until blended. Reserve 1/4 cup frosting for roof and decorations. Frost cake with remaining frosting. With sharp knife, cut peaks in one short side of each of 2 graham crackers. Insert crackers into cake for front and back of haunted house. Break 1 graham cracker in half crosswise; insert into cake for sides of house. Frost 2 graham crackers; place on house for roof.