My modern Scott Classic Specialized Catalog doesn't include this modern stamp and my old 1986 set doesn't list this stamp on color paper. However, my copy clearly has a faint pinkish color. I think the gum is original and the stamp was lightly hinged by a previous owner. There also appears to be a short repaired tear visible from the back side. It's located among the fronds of the palm tree on the left. In fact, that tear seems to line up with a rib of one of the fronds and I can't see it from the face of the stamp.
Does anyone have any information regarding this stamp being printed on pink paper? Or is there another likely cause for the pinkish color cast?
The pink cast is more apparent when viewed next to the other stamps in the set.