George Washington 1 Cent Supposed To Be Green Why This One Is Black?

I have got this stamp in the color of Black? is it Black or something like the color has faded?..

The picture is one scanned and one taken by phone camera,

The second picture is clearly green to me


Peter

The stamp color likely darkened from exposure to the elements (possibly oxidation).

If this green to black is due to sufuretting/oxidation would peroxide bring back the green color?

I've treated many orange stamps with peroxide, but no green ones.

For more info, check Stamp Smarter:

https://stampsmarter.org/learning/H...idation.html

The first photo definitely looks black but the second clearly looks green to me. It looks like two photos of the same stamp when looking at the details but other than the background color are there any other difference in the photos? Was one a scan and the other a photo or was the lighting different? The red mark in the upper left and right corners seem to stand out more in the top photo, are the color levels skewed in that photo?

Why is it black? Those things, color-changelings, can happen with green stamps: