World War I color photos

I didn't know there were color photos from WWI, but it seems there are.
These photos were made with one of the first color photo techniques called Autochrome Lumière. I would have liked to have seen more photos of the trenches, preferably in the rain.

Another early photography technique was developed by Prokudin-Gorsky and used three color filters to produce three black and white images which could be combined to a color image. He used his techniques to document early Russia.