Could tick medicine used on a pregnant dog change the color of her puppies?

[oceantiger]

So, the topical tick medication was put on our dog before we knew she was pregnant. The stuff is supposed to go into the bloodstream to protect against the bugs, so we were kind of worried it would affect the puppies. They came out perfectly normal, however, and developed fine. The only strange part was that the three puppies were all light tan, when the mother (a mini pinscher) is black, and the father (a mini pinscher mix) is also black. The father is a mix, so we just left it at that, but then the mother got pregnant again, with the same father (he has since been fixed), and all three of these new puppies are black. So, my question is, could the tick medicine have affected the color of the first litter puppies?