Yellow colour of egg is due to

Yellow colour of egg is due to Xanthophyll.
The yolk is the nutrient-bearing portion of the egg whose primary function is to supply food for the development of the embryo.
Egg yolk is a source of lecithin, as well as egg oil, for cosmetic and pharmaceutical applications. Based on weight, egg yolk contains about 9% lecithin.
The yellow color is due to lutein and zeaxanthin, which are yellow or orange carotenoids known as xanthophylls.