The last one and most interesting translated from
https://www.greelane.com/nl/science-tech-math/wetenschap/how-to-change-egg-yolk-color-607441/
Changing yolk color at the source
When raising chickens, you can change the color of the yolks of the eggs they produce by controlling their diet. In particular, check the carotenoids or xanthophylls they eat.
Carotenoids are pigment molecules found in plants that are responsible for the orange of carrots, red of beets, yellow of marigolds, purple of cabbage, etc. such as BASF's Lucantin (R) Red and Lucantin (R) Yellow.
Natural foods also affect the color of the yolk. Yellows, oranges, reds, and possibly purple can be obtained, but for blues and greens you will likely need to resort to synthetic dyes.
Foods that naturally affect the color of the egg yolk
Yolk color - Ingredient
almost colorless - white cornmeal
pale yolks - wheat, barley
medium yellow yolks - yellow cornmeal, alfalfa flour
deep yellow yolks, - marigold petals, kale, vegetables
orange to red yolks - carrots, tomatoes, red bell peppers
The original table in Dutch:
| Voedingsmiddelen die van nature de kleur van de eigeel beïnvloeden | |
|---|
| Dooier kleur | Ingrediënt |
| bijna kleurloos | witte maïsmeel |
| bleke dooiers | tarwe, gerst |
| middel gele dooiers | gele maïsmeel, alfalfameel |
| diepgele dooiers | goudsbloem bloemblaadjes, boerenkool, groenten |
| oranje tot rode dooiers | wortelen, tomaten, rode paprika’s
|
on the Dutch internet and let you know.
