I am a big fan of whitening. It is conservative and very effective as long as your teeth have enough enamel. The yellow part showing through is most likely the dentin and whitening is intended to work on the enamel portion.
For patients who have lost enamel to the degree that you are...
It is possible for your tooth to lighten with tooth whitening, but the result can be unpredictable. A tooth will darken following trauma because of hemorrhage in the center part of the tooth. This causes the pigment heme to get into the tooth structure from the inside.
An x-ray can't tell you...
Laser is by far the best teeth whitening option out there. Patients leave with no post-op sensitivity. I have used other whitening system and none produce the results, comparatively of the laser. The average tooth shade is 6 to 7 times its original shade. It takes 30 minutes. I have not had 1...