T206 Blue Old Mill

[steve B]

A couple technical points to consider.

There are few common black pigments for printing inks, especially from the 1910 era. The common ones are carbon black and lampblack, both forms of carbon. Neither of those fades. And neither are prone to simple color changes.
Iron gall ink will initially write bluish black, but the real stuff will eventually turn brownish. And it's not typically used for printing. Pens yes, printing no.

India ink can also turn blue, but I've only heard of that on tattoos. And it also isn't used much in printing.

Green and brown are completely different, and can be changed/bleached.


The polar bear blue would have been made by mixing some blue with some black, possibly with other colors added.

I can think of a few scenarios where the wrong color might get used, and if they were producing millions of cards any one of them could have happened.
So it's a very interesting card for a lot of reasons.

Someone proving a point? Wow, if that's it they've done it. And if that's it our hobby just got very complex. I doubt it, but I suppose it's technically possible.

Steve B