Therma-Tru Fiber-Classic Mahogany Collection door and sidelite. Come home to the rich look of Mahogany. The Mahogany Collection is the perfect complement to rich wood tones in your home. The deep Mahogany grain extends the look of real wood to the outside of your home with all the benefits of fiberglass. From curb appeal to convenience, Fiber-Classic entry doors are made to keep up with your lifestyle.