I found this forum while searching the intrernet for some information on the Dufaycolor reseau. I am currently writing a leaflet on how to identify older color photo techniques for my photo preservation colleagues in Norway.
I am museum photographer since 1989 at Levanger Museum, administering a collection of about 600 000 negatives, from the 1860's and nearly up to the present day. We also have a considerable amount of early color photography, among else an important collection of three-color images, both negatives and prints. If you are interested, check out our web site www.levangermuseum.com
You will also find some of our images at Digitalt Museum www.digitaltmuseum.no
I am looking forward to getting acquainted with your community!