Acetone And Copper Test

24 hours brown Wheat cent, left initial and right 24 hours.

I'm going to repeat this test because I'm surprized in the color difference. It didn't turn pink but the color appeared to change. I don't believe my camera settings or light changed but I'm going to repeat to make sure. Something is funky with my white balance....look at my background (white copy paper). I must have put the coin in a slightly different position on the paper.

Being that long ago, probably would have no effect at all. If you mean the same coins and after all those years, Acetone should do nothing except remove new dirt. Hopefully there is no salt left on those coins now.
Thad: I still think there is a possibility it is something your doing and not the Acetone. I've done so many dips in that stuff with Copper coins and no reactions at all. However, never tried it on a new Cent. Although not noted anywhere, I wonder if the outer layer is not just Copper. To save money, the Mint may be telling their suppliers to mix STUFF in with the Copper.
Or your breathing on those coins.
Or something is in the Acetone.
I'm sort of wondering all sorts of possibilities on how Acetone can possibly effect Copper.

May not be an answer to why things change in Acetone but there was an experiment a long time ago. In this experiment an attempt was made to make the purest water possible. Once made it was placed in a very clean glass jar and sealed. Eventually this jar was placed in a Museum somewhere and is now all cloudy. It was discovered that the glass was slowly disolving into the water. Glass is not perfect and does not only disolve but flows as well. Yes it takes time but it may well be possible that even with this type of experiment with Acetone and Copper in a glass container, some of the properties of the glass may be being absorbed into the solution. Knowing the type of glass, all it's properties, etc., may be a necessity in this type of experiment.
From Wikipedia:
The most familiar type of glass, used for centuries in windows and drinking vessels, is soda-lime glass, composed of about 75% silica (SiO2) plus sodium oxide Na2O from soda ash, lime CaO, and several minor additives. Often, the term glass is used in a restricted sense to refer to this specific use.