Subject: Why does a white gold ring turn yellow after it has been sized?

A friend of mine just received a white gold engagement ring from her 
boyfriend.  It was a bit too small so they took it to the jeweler to have 
the ring made larger.  My friend read in a bridal magazine that sometimes 
once a white gold ring has been sized it can discolor.  Hers has turned a 
bit yellow now after the sizing.  The jeweler tells her that sometimes that 
happens and the will polish it and that should help.  It did not.  She 
keeps complaining but they keep giving her the run around.  We do not know 
who to turn to to get a straight answer.  Hope you can help.

Re: Why does a white gold ring turn yellow after it has been sized?