The other thread is a bit patchy, sometimes it gets lots of responses and sometimes not many (probably depends on who is how busy at what time.)
Yes, now that we know he is not the father, it doesn't matter as much.
Yellow skin is recessive to white skin (usually visible on the soles of the feet, regardless of what other colors are on the tops of the feet and on the shanks.)
If both parents have white skin, but carry the gene for yellow skin, then yellow skin is expected to show up in about 1/4 of chicks.
Dark vs. light skin is controlled by a different gene.
"Light" skin gives white or yellow shanks & feet
"Dark skin" gives slate/blue (white skin) or willow/green (yellow skin)
The genes for some feather colors will also make the skin on the shanks darker or lighter (so black chickens often have black shanks, blue chickens often have slightly-lighter shanks, splash or barred chickens often have lighter-yet shanks. The blue gene and the barring gene dilute the shanks as well as the feathers.)
For ths particular chick, I think it has:
--some black on the shanks because of the genes for black feathers (even though it then has the black in its feathers turned to blue)
--yellow skin (recessive gene carried by both parents)
--probably genetically light skin, but I don't trust myself on that when it's got dark areas from the black-feather genes.
Probably just a dark blue, but I don't know for sure. Some blues can be so dark they are almost black.
I agree that it probably has nothing to do with the other points you mentioned, but it's interesting anyway.
Those chicks would be showing the white skin gene.
The ones with slate gray feet might have genetically dark skin, or they might just have unpredictable amounts of dark in the skin from the genes for black feather colors.
Yes, that does really help.
And it's fun to see cute chick photos, too