Which of the following factors usually affects the colour of egg yolk?

The main factor that affects the color of egg yolk is the type of feed that the laying hen eats. The yolk gets its color from pigments found in the foods that the hen consumes, such as yellow and orange pigments from corn, marigold petals, and other yellow and orange plants. If a hen eats a diet rich in yellow and orange pigments, the yolk will be a deeper yellow color. On the other hand, if a hen eats a diet that lacks these pigments, the yolk will be lighter in color. The other factors, such as the age of the hen and the type of housing, may also have some impact, but to a much lesser extent compared to the type of feed.