Yellow Enamel. I Have Done the Tray Thing That Doctor Sold?

Bonding or veneers can be done without prepping (removing enamel) the teeth but that does add some bulk.  You can also have the dentist increase the % of the bleaching solution.  Sometimes etching the teeth before bleaching will give better results.

It sounds as though the bleaching trays did not work well for you.  I would consider doing Zoom Whitening as an alternative.  The results are typically much better than bleaching trays alone.  This procedure is performed in the dental office and takes between 90-120 minutes. Hope this helps.   

The KoR Whitening system has provided the best results for my patients. It  works by restoring your teeth's ability to absorb oxygen. The oxygen from the whitening gel is absorbed deeply into the teeth, dissolbving stain molecules. It's reliable & effective.