Last year I remember somebody recommended a leather couch restore kit, couldn’t find the topic anymore. If you have recommendation of leather couch restore ideas or kit, please let me know, will be appreciated.
I did my dark red sofas last year, and the off-white ones this year. The color is holding up well. I had to use the liquid rubber repair part of it on the red sofas - the leather was very old (30 years) and had cracked - and that isn’t holding up as well as I hoped. So my assessment is that it’s great for color issues and scratches and probably damage, but it’s not a permanent fix for old age.
I use a large red felt ink marker to fill in scratches on my red leather sofa.
@Ping - if you possibly can, try to send them a small piece of leather (look under the cushions for a little piece that’s sometimes there, or under the couch where they stapled the leather to the frame) so they can tell you which color you need or custom-mix it for you. My experience is that it will take a lot of dye if you end up changing the color very much, and especially if you are a perfectionist…