The possibilities are almost endless. If the stallion is not homozygous for black, he could throw either black based or red based foals. If he is not homozygous for one of the pinto patterns, he could throw either pinto or solid foals.
Assuming the stallion is not homozygous for either black or pinto, AND assuming the chestnut mare is a true chestnut (and not silver bay) and assuming she is not homozygous for pinto, you would have a 50/50 chance of a black based foal and a 75% chance of it being pinto (of course, if either parent carries another pinto gene in addition to tobiano, the chances will increase). If the mare carries a silver gene or agouti gene (either of which would be hidden in chestnut) you have a chance of a silver foal or a bay foal IF the stallion throws the black gene.
From the white mare, IF she is a maximum sabino or maximum splash, you will most likely get a pinto foal, either black based or red based, depending on which genes each parent throws. IF she is a cremello or perlino, you could get chances of buckskin or palomino added.
From the silver bay mare (if she is solid) you would have a 50/50 chance of pinto foal. Assuming she has one black and one red gene, you would have a 75% chance of a black based foal which could include black, silver, bay, or silver bay.
If the stallion has a hidden cream gene, there could be numerous other posibilities. ALMOST ENDLESS!
