Paul, there must have been some misunderstanding as to what was said. The yellow pigment, , a form of xanthophyll, actually is stored in the skin. As a hen lays more and more eggs, the xanthophyll is drained from the system, deposited in the yolks, and the yellow skinned legs and skin become pale. The egg yolks would become paler also. It is re-established in the system while the birds are not laying by eating plant material that contains it, such as green grass, corn, etc. For that reason a willow shanked bird that is a good layer will often change to a slate shanked bird, since the yellow part that makes up willow disappears. It does not change genetically, however. I do not remember ever saying blue is stored in the visible parts of a chicken; if it did, why would the legs not become pale after an Ameraucana lays lots of eggs? I am truly sorry if I misled you.