I've seen people comment numerous times about the so-called "violet" colors of the 1st issues, asking if a particular hue was normal.
Scott #:
R22 - 4c Proprietary
R51 - 30c Foreign Exchange
R52 - 30c Inland Exchange
R80 - $1.90 Foreign Exchange
R84 - $2.50 Inland Exchange
(I would also put R21 - 4c Playing Cards in that group as well, even through it is listed as "slate", as its colors can also occur in a rather wide range).
I don't know if the biggest problem was the instability of the pigment and vulnerability to environmental exposure, or that it was just a difficult ink to mix and quality control was scant given the time pressure the workers were under to produce these stamps. The colors range from violet to brown to gray to even blue and blue green (although these last two tend to appear to be environmental changelings).
I happened to be looking through one of the stockbooks from my 2014 hoard purchase (much of it still unchecked even after a decade) and came across this 4-page grouping of R22c that perfectly encapsulates the variety of colors.
My apologies for the poor lighting and cellphone pics, but hopefully the pictures serve their purpose.
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