Tooth Color Change After Veneer Replaced, could the clear glue have traveled?

these cements are made up of resins and with time tend to changes shade. so suppose yr doctor use same type and brand of cement after few years there r chances of shade difference. 

Hi:It is definitely a coincidence.  The glue can not travel from one tooth to another.  Best,Dr. Maddahi

There is no way the cement traveled to other teeth. You're probably noticing your teeth more now that something has changed. Over time, certain cements can slowly change color which can bleed through the veneers. I would discuss this with your dentist, but rest assured, it's not because of the new cement.