Toned Nickel Proofs - Your Opinion: Natural?

I hate to see a member not get any response. I will give it a shot.

I think most members here have not replied because it would be hard to judge between
toning and artificial toning (AT). Pictures may help.

I can tell you, I have seen nickels that have natural tone in colors from blue, purple yellow/gold.
Some will also go to dark shades like brown and black.

Some of the Jefferson's I have that came from a proof only Dansco or Whitman folder with the plastic sheet windows have acquired a nice light golden blue tone around the inside of the rim.
I don't think that the more recent nickels tone this way in the original plastic display cases they come in. They tended to get a milky film in the type of cello they were packaged in in the early 60's to mid 50's and often they turned downright ugly and dark in the early 1950's. Especially those that came in small square boxes and cello sleeves.
I think now that they are being packaged in cardboard and plastic, we might see a lot of golden toned nickels as time goes by develop. The coin and currency sets of 1994 and 1997 have nickels that tend to tone this way due to the packaging although they are not exactly proof coins.