Why is the milk of buffaloes white and cows have yellow milk?

Milk from both buffaloes and cows is usually white. Sometimes however, cow milk can have a yellowish tint due to the presence of beta-carotene which is a pigment found in plants. Beta-carotene is what gives carrots their orange colour. When cows eat diets rich in beta-carotene, such as fresh green grass or hay, their milk can become yellow. The yellow color is not harmful and does not affect the taste or quality of the milk.