There is somethings fishy with black and white photography: it got color. I have three old glass plates which I either photographed (in color) in a window (the soldier in wearing a cap) or I scanned them as non transparent plates. (the lamp in scanner won't start if I haven't got a special film holder installed, but these just plates don't fit).
What happens ( at least in he scanner) is that registers the surfaces of the plates as if they were non transparent. Yes, off course i inverter the photographs, otherwise you would haver seen the negatives. And yes, once again, I tweaked them color wise in Photoshop, but I did not put in something new, the colors were all there, but a little subdued.
The biggest surprise I got from grandfather. I seen his stern face from the same negative most of life; having in my fathers office or in his study at home, but here surrounded by a pastel colored frame he seems less frightening. I never met him, but I think most people didn't smile into the camera of professional photographers in those days! (early 20th century) The last pic is the least dramatic, just a nice blush ting with some yellow red on the side. I used for a little montage called Happy Together Again! [link]
But where, in these black and white photos, do the colors come from? I am not into chemistry! Any ideas?