Then I understood you correctly. Of course orange leather, on a phone case, will not stay orange. Orange is basically just a lighter shade of brown so it will inevitably turn into a more brownish shade.
Same goes for suede, eventually those tiny hairs will of course rub off due to friction and you're left with a smooth leather. That is why all suede shoes will be completely smooth where the creasing happens from front area bending.
Even the color changing THAT quickly can be explained, but that I feel is something that should actually be mentioned and that goes for every case manufacturer. There's very few that mention how the leather has been dyed. There's aniline dyed which happens during the tanning process and the color sits way deeper and then there's crust leather which is delivered white and then dyed after the fact, which makes the coloring way more surface based and more prone to change. Crust leather is popular for smaller volumes because they don't need to stock multiple colors of something that might not sell out that fast.