Colors of Milk: While drinking milk or having tea and coffee, have you ever wondered why it is white, not red, green or any other colour? Has any child ever asked you that cows and buffaloes eat green grass, then why is the color of their milk white? First of all, let’s understand what is milk? Milk is an emulsion of milkfat globules in an aqueous environment. The aqueous portion of milk contains many substances including lactose, proteins, minerals and vitamins.