Can I change E-max veneer colour after bonded them?

I've used E-max veneers for a couple of years now and I love them. They are much stronger than traditional veneers and fit extremely accurately and most of the time when a master ceramist has done the work, looks absolutely beautiful. However, I have also noticed that they have a slight tendency to look more gray than Empress or feldspathic porcelains.Most cosmetic dentists will give you the opportunity to view the veneer prior to bonding it into place. If you don't approve of it, it is much easier to return to the lab to make appropriate changes. Problem here is that once the veneer is bonded it cannot be removed without destroying it and then you would need to get a completely new veneer made. Most cosmetic dentists don't really like the technique of using whiter cement, however it can make a color shift (change) in the shade of the veneers. It is better and more color stable to just change the color of Emax porcelain (called the "ingot" shade), possibly doing a little more tooth preparation to give the ceramist more room to whiten the teeth to meet your goals and expectations.