What are all the color possibilities?
And would they all be short hair?
*red heeler is out of one blue parent and one red parent
Not totally sure (Ask me about cat genetics. That I can answer, but I believe blue is the dilute of black (going back to dogs now and pretending these are shelties.) so your red heeler would carry the blue recessively. Since it is recessive, if both prospective parents (the heeler and border collie) carry the blue gene, there would be the possibility of a quarter of the puppies being blue and of the red puppies would have a 2/3 chance of carrying the gene or if you counted all the puppies, 50% would carry recessively. Of course that is on average so it could also be all or none.