my yolks do not seem to be as dark and bright as they were when they first satrted laying. granted, they are not milky yellow like from the store. but they are still not the "orange" that i feel they should be. any specific nutrient you think they are missing? they get a layer crumble, occasional kitchen scraps, BOSS, and once a day they get cracked corn(maybe 1/2 C. total for all 4 hens), and they get out in the yard on the weekends when i am home and can watch them. thank you for your advise.