After thinking about these results for a while, you realize based on your previous work that there are actually different mechanisms for a canary to end up with yellow plumage. Either the canary is homozygous recessive for gene A, in which case it is not capable to produce any darker pigment, or it can produce the pigment, but it is homozygous recessive for gene B, and hence the resulting pigment is never inserted (expressed) in the developing feathers. For each of the 5 possible outcomes resulting from a cross of a yellow F2 canary with a pied F1 canary, identify which mechanism was responsible for the plumage color in your yellow F2 parent that you used in the cross.