I had a pair of JC nude patent leather wedges which went that icky yellow/mustard-y colour after just a couple of years. I was told by several shoe restoration places here in Australia that they couldn't ever get them back to the original colour and any attempts to dye a darker colour could not be guaranteed to be satisfactory.
They sat in my wardrobe for another 5 years or so until one day I pulled them out and figured I had nothing to lose by going at them myself as they were only taking up storage space as they were.
I do a lot of crafting, so have a selection of alcohol inks in various colours. I used Jacquard Pinata brand alcohol ink which is available at any craft store.
I took a small paint brush and squirted some blue-violet alcohol ink into a cup and went for it. It dries almost instantly so I had to be really careful not to get it anywhere I didnt want recoloured. Next time I'll use some kind of masking tape, even though it's not too bad this time.
When they came out looking surprisingly good, I thought, "they will probably make my feet turn blue when I wear them, this is too good to be true". I was sure the ink would somehow transfer to my skin if my feet got the slightest bit sweaty, However I was very pleasantly surprised to find that not even the teeniest bit of transference happened!
I've since worn them 3 or 4 times for several hours at a time and still no issues with the colour transferring, bleeding or anything else it shouldn't do.
Very happy to be able to wear them again after so long having them stuffed in a cupboard. I'll never buy nude patent leather anything again, as it's quite apparent that the discolouration happens quite a lot with other brands too.
So, just thought I would share this, in case anyone else was at the "nothing to lose" point with their patent leather stuff!