Color Photography Explained-6
This shows another phase of the recomposition, being the green and red separation plates printed in their complementary pink and blue. It will be noted that in the last picture the pink and yellow combine to make the spectral red, which has no blue in it; while in this picture the pink and blue-green combine to make the spectral blue-violet, which has no yellow in it.
This image is from: Luther Burbank: his methods and discoveries and their practical application. Volume 12 Chapter 6