In most cases they are not dyed to an unnatural color. Dying is done to give color uniformity. Often during fermentation wrappers become "splotchy" and unappealing. Wrappers are the most valuable leaf from the tobacco plant and wasting them due to uneven fermentation would increase cost. Aesthetics are a big part of any consumer purchase, from televisions and food products to cigars. Some of the cigars accused of being dyed, Partagas Black, Sancho Panza Double Maduro and Padron were among my favorite maduros. I dont smoke many NC's currently, but I would not hesitate to put them back in rotation.