No. Yellow teeth aren’t permanent and can be whitened. Dr. Bill Dorfman, a cosmetic dentist, says, “Of all the colors that are considered discolored teeth, yellow is typically the easiest to whiten. If you have gray teeth, they won’t whiten very well with either professional or take-home systems. But, yellow teeth tend to be the most easily corrected with either professional in-office tooth whitening or any of the take-home tooth whitening options. So, the answer is ‘No,’ they do not have to be permanent.”