United States: 1896 copper-nickel proof 5-cents, Liberty Head type PCGS PR64. Cert. #44818008. Numista-3683, Krause-Mishler-112. Mintage: 1,862. Ex-eBay, 15 July 2022. I am not always an enthusiast of heavily toned coins. Sometimes I am and sometimes I'm not- it really depends on the pattern of the toning and whether or not it distracts one's attention from the design elements of the coin. On the other hand, lightly toned coins like this, with pastel colors like we see here, do really appeal to me. Especially when the toning has a "bullseye" or "target-toned" pattern. This coin has that, albeit in a rather understated and subtle way. 039500
What amazes me the most is the dedication and care in protecting these little numismatic gems over all the years.
Well, I expect you'll see that more often with proof coins, since they were made for and saved by collectors from the beginning, rather than being issued for circulation.