Great reply! Makes a lot sense. Thank you.
Well, just came to my mind. Would possibly mostly white content of wheat reduce the egg yoke color (since yellow corn, normally has a lot of yellow color)?!
In the meantime I found that yellow corn in the feed does help yoke to have more yellow/orange color because the corn has large amount of carotene.
I found this article which discusses other food which can be fed to chickens to get more yellow color of yoke:
https://www.agriculture.com/family/living-the-country-life/getting-chickens-in-the-fall
my run is pretty large, 5 square feet with lot of green plants growing, which should help.
I understand that the only nutritional advantage of darker yellow/orange color of yoke is that it has more carotene and thus vitamin A.
potentiall I can decide to go with 25% K122, 25% corn and 50% wheat.