The best answer to this would be proper and consistent cleaning and maintenance. A big part of leather care is damage prevention, which will include keeping your leather chair away from direct sunlight or from direct sources of heat (like your heating vent) and staying away from harsh chemicals when cleaning the leather fabric, among others. Always use the right cleaner for your leather. And when you notice fading, you can simply use a leather restoration kit to bring back life in your ergonomic leather office chair.