Fee

Fee is a dilution mutation that changes the brown plumage in quail to be grey, black, and white. It does not change the pattern of the feathers itself, but rather the underlying color. It goes by a variety of names, including Falb Fee (on Pharaoh), Pearl Fee (on Fawn), and Grau Fee (on EB). These names don't differentiate between heterozygous (one copy) or homozgyous (two copies) of fee, it's all just called Fee.

Heterozygous Fee (Left), Homozygous Fee (Right)

In homozygous form (two copies), the bird will be entirely black, white, and shades of grey. In hetero form (one copy of fee, one "natural"), the plumage will be mainly shades of black and white, though there will be some color leakage. In both forms, the fee is clearly visible.

Homozygous Fee x Homozygous Fee = 100% Homozygous Fee

Homozygous Fee x Non-Fee = 100% Heterozygous Fee

Homozygous Fee x Het. Fee = 50% Homo. Fee, 50% Het. Fee

Het. Fee x Het. Fee = 25% non-fee, 50% het. Fee, 25% homozygous Fee

Het. Fee x Non-Fee = 50% non-fee, 50% het. Fee

For more information about breeding with this kind of gene, including tips and tricks and a full explanation of how these results were calculated, please see here.