So I was at the Nelson-Atkins Museum yesterday in Kansas City and they had a modern daguerrotype of a park scene and the sky was distinctly blue! My girlfriend thought that the cherry blossoms looked slightly pink as well. I've heard of daguerrotypes exhibiting "spontaneous" color, even in the far distant past, but no one seemed to be able to get repeatable results. There's a write up somewhere in the tubes (the internet that is) about this and one man's modern efforts.
Anyways, just an interesting aside to the world of interference color photography.
I'd love to get my hands on those translations by the way, if either Lionel or Ray are willing.
UDPATE..... ok, I contacted the museum and here is the guy.... http://www.jerryspagnoli.com/ I haven't read much yet, and I'm not sure if it's "true color" interference or more of a solarization effect. Either way, it's worth looking at.