I don’t know why I was worried about mixing colors. I always had this idea that the water content in an anthotype emulsion would wash away an underlying color.
I started coating another sheet of Fabriano with onionskin and ran out of time before the solution got too ripe with bacteria. After about six coats I had to toss the old onionskin solution. Soon afterwards I got either stupid or courageous and decided to open a can of beets and apply the beet water to the paper.
Voilà! Salmon resulted and the layers didn’t really wash each other away. It’s like I’m learning how to make watercolors.
This does create some new possibilities and problems. I can go back and add a different color on top of an already finished anthotype and purposely put it out of registration (these are essentially photograms).