The colour which is a pigment (posh word for leather paint) simply wears off and can simply be put back. BTW, it is not a dye.
I have an advantage because I restore leather colour as part of my business - but I do not do cars, and have no intention of doing them. Just wanted to make that clear to the Admins that I am not interested in gaining any work off of here whatsoever.
First of all you need to get a sample of the leather - I got mine from inbetween the seat and back cushion with the back seat fully extended down as far as it can go. Then get it sent off to a leather supplier (I use
http://www.buffaloleather.co.uk/ - I have no links to them or anything like that). They analyse the sample and then send you back the liquid pigment as a 100% match. And it HAS to be 100%. At the same time you could order an aerosol spray lacquer in your choice of finish (matt, satin, gloss). This solvent based lacquer really seals it all in and is very durable. I personally like to also use aPU water based finish (matt) on top of that to give a true matt finish and nice feel.
To do it you need to clean the leather with strong leather cleaner with either a brush to get in to the grain or a magic sponge (BTW a magic sponge should never be used to just clean leather). Once all the dirt has been removed, then wipe over quickly with isopropyl alcohol (off ebay) using a big wad of tissue paper/kitchen towel. You don't need much.
This sterilises the leather and will make adhesion even better. Then using micro rollers and a small paint tray, roll on to the leather - not too much, in an even coverage. Then either leave to dry naturally or use a hair dryer.
Once completed use the lacquer of your choice and put on 2 coats. Again, dry as usual.
Now I know this might all sound complicated but if your good with your eyes and hands, an excellent finish can be achieved.
The old chap that had my 75 was poorly and he used the steering wheel to lever himself in and out, and so wore the leather colour down.
Hope this helps.
