The durability of leather couches cannot be denied by those who are familiar with them, but years of faithful service can render a couch worn-, faded- and distressed-looking. Fading, or the loss of the original colour of the leather, is often caused by the cleaning solutions that are used and exposure to sun rays. Regular maintenance of your leather couch can often delay the wearing process, but it will eventually happen. Once it does, it's fairly simple to restore the leather couch to its original colour.
Clean your leather couch thoroughly with a dampened sponge, using a solution of mild dish detergent dissolved in warm water. All dirt, body oil, food stains and other contaminants must be removed so the colouring solution will properly adhere to the leather.
Apply a layer of leather prep solution to the entire couch with a soft cloth, and then scrub the surface of the leather gently to open the pores. Work in small sections so the solution does not dry out on the leather before you are done with it. Allow the couch to dry completely, which usually takes between 15 minutes to an hour.
Sand the leather softly, scuffing the surface slightly. Avoid deeply abrading the leather as that will necessitate further repairs. Using too much pressure will cause deep scratches in the leather couch. The seams of the couch can begin to fray if you sand over them, so work close to them -- but don't sand over them. Wipe the sanding dust from the leather couch with a slightly dampened sponge, and allow the material to dry.
Spray a light, even coat of the leather colour coat over the couch, working on one section at a time. This works best if you work on a predefined section; for example, one cushion or one arm at a time. Spraying long strokes will allow you to cover the area thoroughly without overlapping or skipping places. Apply three to four coats of colour to restore the leather couch to its original colour, allowing the dye to dry in between applications. Allow the couch to remain undisturbed for 48 hours.
Massage leather conditioner into the whole couch using a soft, lint-free cloth. Use an ample amount of the conditioner, ensuring that you cover the cracks and seams of the couch, too. Wipe away excess leather conditioner with a clean cloth to avoid transfer to clothing and skin. Wait at least two hours before using the couch for the conditioner to dry completely.