In a type of parakeet known as a "budgie", feather color is controlled by two genes. A yellow pigment is synthesized under control of a dominant allele Y. Recessive homozygotes with the yy genotype homozygous do not synthesize yellow pigment. At an independently assorting gene, the dominant allele B directs synthesis of a blue pigment. Recessive homozygotes with the bb genotype do not produce blue pigment. Budgies that produce both yellow and blue pigments have green feathers; those that produce only the yellow pigment or only the blue pigment have yellow or blue feathers, respectively; and budgies that produce neither pigment are white (albino). A cross of a green budgie and a yellow budgie produces offspring that are 12 green, 4 blue, 13 yellow, and 3 albino. What are the genotypes of the parents?