Why Is #1503 Lbj So Green?

I don't think I have any error stamps but if this is one, I goofed!
I cut off the corner of the envelope that had a nice stamp. But as soon as I cut it off and clipped the damaged (upper left) LBJ at the same time I realized that LBJ looked a little green all over.
A normal 1503 is there for comparison.

Somebody please tell me that I didn't ruin the only error stamp I might ever have!

I don't know why they are like this, water maybe, but what's sad is that stamp in very badly damaged, the surface damage in upper left corner and appears to be a scissor cut on the right side.

Mike

I am not sure but could the colour change be due to some copper chemical substance in the ink that is oxidizing so it changes to green (verdigris)?

Or a chemical in the atmosphere, the air, acid rain kind of? Gremlins? The Borg? I bought a Canadian stamp that had changed colour (and I have managed to lose it somehow!) and it was a greenish changling also. I have always wondered about that.

I think he had some bad tacos for lunch!

Mike, the scissors cut is my doing. After all that I have learned on this forum, I should have known better than to cut the envelope.

Puzzler, I had thought it might be a color variation but I had not considered an oxidizing possibility.

I knew that some orange stamps like #558 and #638 6 cent Garfield oxidized to a tan or brownish color. Maybe you're correct that LBJ is oxidizing to green.

BTW, too many tacos would turn me green too.

Marty

This issue is notorious for unintended color variations, especially since the background is actually a mix of colors. I don't think it was oxidation. I think that one of the colors was simply under-inked.

This could also be a changling, caused by exposure to sunlight.

David

Thanks everyone, I'm feeling better already.

But I really need to be much more careful in the future.

Marty