I brush my teeth two or three times a day and they are still yellow. What to do?

Whitening strips. I am not a dentist, but here is what works for me. Be sure to get regular cleanings at the dentist. Avoid cola, tea and coffee. Avoid blueberries. Floss every day. Do not brush too hard or you may damage your teeth and gums. Over the counter whitening strips can help remove the yellow color. Use as directed.
Whitening . Brushing alone is not enough to whiten your teeth. Even if you are using whitening toothpaste. If you want a whiter smile the best results will come from having your dentist professionally whiten them. Over the counter products like white strips will give you some help.
Whitening. Through normal eating and drinking, teeth stain over time (some foods and drinks affect teeth color more than others). The only way to lighten teeth is to whiten them. There are many whitening options available- from professional whitening in the office or take home trays, to the less effective otc options.
Bleach your teeth. Natural tooth color is somewhat yellow. Genetically some peoples teeth show up more yellow than others. If it has been 1 year or more since your last dental office cleaning, you should get one. Next havethe dentist evaluate you for home bleaching or inoffice bleaching for your teeth. This is the best way with usually the best results.
Zoom or Sapphire. Straight, white teeth; some new solutions have arrived... New zoom whitespeed! results on people we tested are very good. Also our patient's favorite these days; low sensitivity, advanced technology, sapphire. Both are sometimes referred to as laser whitening. We have not seen the tooth sensitivity which was typical for great whitening previously, as the technology keeps improving.