OK, I am going to take a stab at this just to see if I am right. I could be totally wrong BUT the Ritterspach website says Wilson White is an "incomplete dominant" and goes on to say that all white mosaics and silver mosaics are a form of wilson white. So I guess you would put in white and standard for the dam at Silverfall.
As for the father, does he have a white belly? Or is he all one general color? I thought that in order to be a beige the chin HAS to have a white belly, otherwise he would be almost certainly be some shade of tan.
If I am right in what I have then according to Silverfall you have 12 color possibilities, the most likely of which would tan, ebony, tan white, or ebony white, IF the father is a tan. IF he is a beige then you have equal chance of getting standard, hetero-beige, pink white, or mosaic.
This brings me to a question of my own. How does one decide whether a chin is light, medium, or dark in color? Is this just a judgement thing?