Influenced by the media ads, we would not even question the assertion that healthy teeth should be compulsory White. In fact, according to German dentists, teeth color, as well as eye color or hair, is a personal characteristic of each person.
Moreover, pure white teeth from nature simply do not exist. Their natural color ranges from yellow to grayish blue. Therefore the "white teeth" fashion is like popularity of blonds, although dyed blonds
However, the myth that healthy teeth are white teeth, stays in our soubconscious very deep. And hardly anyone would argue the doctors' claim that the yellowish enamel is much stronger than the white one.
But before whitening the discolored teeth from smoking or coffee, as well as a yellow nature of the teeth, remember that such operations are harmful to enamel.