I just started to work with Sam's method and have made one good print. I invert the image and then split channels and have a gray scale for RGB. Red=Cyan,Green=Magenta and blue=yellow. I put about six coats of yellow and red layers over the cyanatype. Need to find a better red for the one I am using is to red/orange. With a true red color correction would would take less effort and layers. Since I am new to gum printing I am going through different pigments and how they work with the gum.
So Sam's article is a good starting point, just a matter of time finding the right combinations of pigment layers and exospore for each layer.