I would classify that as a harsh effect of renomat. It has pulled off most of the finishing. It is easy to replace the colour in ur particular brand and colour of shoe.
Dark brown and black are easy to do as @benhour said. It’s much more difficult if u have a crust leather with hand painted finishing. Or if u have a specific patina done by hand or a unique color.
PS: those are lovely shoes and I am happy to see u have got such good results.
I don’t think it actually pulled the finish off, but just dried it out. When leather is dried, it becomes very light. You can see the opposite effect when a dried shoe is moisturized—the leather darkens. In this case, all the original color returned when I applied the Renovateur, which has no color itself.