Help Please With Berlin Michel #47 - Color

I can only find information about this stamp in yellow-green or light green. The stamp on the right is dark green. Can anyone help with an ID?

My specialist SG catalogue calls this issue "bright green". However, your colour difference is very striking. The 10pf was issued in booklets. Maybe this accounts for the difference? Green is a notoriously unstable colour so maybe it has been affected by climatic changes?

Michel lists the lighter green. I suspect your darker green has been affected by something chemical or environmental.

The stamp paper is stained dull pink on the darker stamp. Pink + light green = dark green.

Thanks much - I appreciate all your replies.

This is the reverse. Does it look stained? The top right looks to me like a bit of toning. Just out of curiosity, what sort of chemical would cause a stamp to darken?

The dk. green is a type II,Mi.47II

Other differences with these stamps:
1st pic your stamp.Notice the lower solid line is straight in your
stamp.In the 2nd pic varient; the last row of horiz. lines are sitting on top of the line.

Actually, both of these stamps are Michel 47 type II's, i.e. coil stamps. The horizontal shading lines between the "0" of 10 are distinctly defined and separate from the type, and the last dash of the shading above "P" of POST ends over the "P" rather than before it (type I). The "S" of KLEISTPARK is also a little different, but this is not so easy to see. The last row of shading under the"10" (six dots) are continuous on type II, rather than in groupings of 2, as in type I (perf12's mint example). But again, this is not easy to see from the scan.

Michel lists #47 type I at .50, while the type II's (coils) are at 8.00 euros.

Still, I believe the right stamp has been soaked off a colored envelope...or with stamps that were on colored envelopes.