If you brush your teeth every day and your teeth are still yellow, it may be due to the yellowish color of the teeth themselves, or due to the presence of calculus or pigmentation. 1. The reason why teeth are yellow despite daily brushing is that the color of dentin itself is yellowish, so it is possible that some teeth are born with a yellowish color. 2. If there is calculus on the teeth, it will produce yellowing phenomenon, which can be removed by way of scaling. 3. If you drink too much coffee, strong tea, etc., you can have yellowish teeth, and you should rinse your mouth with water more often, or you can polish your teeth and whiten your teeth with cold light. If the phenomenon of yellowish teeth color, you should go to the hospital in time for examination.