From what I understand the "French Black Copper Maran" birds have the feathered feet and lay the darkest of all the eggs. Then there are the "Black Copper Maran" bird that DO NOT have the feathered feet but still lay dark eggs.
I also have light brahmas and none of my feather footed birds have or had feet problems or mites. I hope this helps.
I also have light brahmas and none of my feather footed birds have or had feet problems or mites. I hope this helps.