is it possible for 2 black and white bostons to produce seal and white puppies?
I don't know - I think it would depend on their lines - what is in their parents color schemes? What colors were the litter mates - grandparents - etc?
The parents of my male were black with a little brindle, so he's mostly black with just a little brindle, my females parents had alot more brindle, so she has more brindle in her coat. the grandparents, i couldnt tell ya... haha
Are these dogs breeding material? If they are you would definitely know about the grandparents coloring.
the short answer is yes...if both carry it recessively. If one does not...then no.
To know if one or both carry it recessively you would need to know their pedigrees well enough to where this question would already have been answerable.
I own Boston Terriers and yes it's possible. You'd really have to look into the pedigree and you'd probably find dogs of seal color in it. In fact, it's much harder to get black, without any brindle whatsoever, and white.