My daughter is entering her science fair and has decided to use our hens and their eggs as her test subjects. She wants to see if what she feeds them will affect the color of the yolks. The science fair is next month, so I was wondering how long it would take before we saw any changes in the yolk color? We started feeding them the different things she wanted to try yesterday, now I’m just curious how long it will be before we should expect any changes (if any at all)? Did we start early enough? Thanks for your input!