I had similar initial "wear" on my "P" button. Put XPEL disks on the buttons. Since then, no additional wear in the past 1.5yr.
Will eventually replace once I get to it.
However, if it is just thermally induced discoloring as noted by milehigh then it may not help in the long run unless
it is an interaction with between perspiration/heat/paint.
My 2.0 also had the silver accent paint on all the air vents wear away in parts from the previous owner. I replaced those.
Interesting with those is that I found you can replace them with the Alfa 4C spider vents. They are the same (even molded ID numbers) except the chrome ring is not shiny silver, but rather a more matte silver which matches much better to the matte silver door pulls, the matte silver accents on the newer CF sills and the matte silver on the shifter console. I kept the originals for future use.