Quote: A gene (actualy an allele, that is, a variation, of a gene) is or is not recessive. Can't change it. What can happen is that over time all the birds in a flock may inherit two copies of the recessive alleles and consistently display the recessive trait as a result. It really depends on which birds are kept and which ones are removed from the breeding pool. But breed that double recessive bird to a bird that only has the dominant allele, and the dominant allele will display every time.
Almost all white silkies are recessive white. With the caveot that if they have a paint background, all bets are off on that.