Regarding the tires - I know. Rubber degrades over time regardless of storage, and same goes for seals, bushings, gaskets, tires, whatever we're talking about.
I'll change the tires soon, it is on the list. The only reason why I didn't do it as a priority is because I'm not going high speeds with the car, but it's on the list
After our discussion about the color and the color code, I went and checked the color code and it's not K51.
This is the passenger side sticker:
From what I can google, KAC is a color code for "Desert shadow" color.