Is there a way to tell het pied on appearance?

[asplundii]

I don't think pied is text book recessive but rather in a gray area with sporadic co-dominant tendencies. Maybe it's as simple as there being several different normal alleles of the piebald gene and the pied mutation can be either recessive or co-dominant depending on which "normal" allele it's paired with.

Now there is an interesting idea. Sort of like the "hidden" gene in the platty complex... Silent when paired with the true WT allele but causing the marker when paired with a pied allele... Very interesting...