Is There Any Way to Whiten Veneers?

Porcelain veneers are stain resistant and should not change in color.   If it seems like the veneers are getting darker, many times this is a sign the underlying tooth is darkening and other times the space between the veneer and natural tooth is open and perhaps the veneer margins are leaking yielding a darker veneer,  In both of these instances a new veneer(s) is needed to correct the discoloring and integrity of the veneer.

Porcelain veneers will not change color and can't be bleached.  If you feel that they have turned darker you either have leakage underneath the veneers or the natural tooth is turning dark under the veneers.  Either of these caused can only be corrected by replacing the veneers.  Good luck.

One of the great things about dental materials today is their color stability. This is also one of the downsides; veneers won't change.
Tooth structure beneath veneers can darken over time, and if the veneers are super-thin, the result can be a darker smile.
Bleaching the underlying tooth structure can be very challenging, so the most predictable way to improve the smile is to redo the veneers.

You have a few options.
1 A professional dentist can whiten your teeth from behind 
2 whitening strips can remove lighter stains from the front part of the porcelain veneers.
3 We have a special paste that we use to brighten up veneers and give them back their shine, that's usually done at a prophylaxis appointment.
Hope this helps 
Joseph Goodman DDS, Beverly Hills 

I would recommend seeking professional consultation. There is a technique by which you could bleach the back side of the veneers using a custom-made tray designed especially for this purpose.