It is normal for kittens’ hair to turn yellow. Because when a cat is in the moulting stage, its hair is determined by the genes of its parents. If the previous generations had yellow hair, the cat's hair will turn yellow when it moults. If a cat's parents or grandparents have yellow hair, the genetic determination cannot be changed.

If adult cats are fed low-quality cat food or food with low protein content for a long time, their hair will turn yellow because they will not be able to obtain sufficient energy from the food for their daily needs. Protein, lecithin and vitamins are called the three major nutrients for cats. If a cat is deficient in these nutrients, it will be prone to yellowing of hair.

If the cat is not dewormed regularly, it will be easily infected with parasites, and the parasites will rob the cat of nutrients, causing the cat to be malnourished and its hair to turn yellow. Cats should be dewormed regularly, generally once a month. However, the specific frequency of eviction depends on the specific situation.