Feeling my crowns crackling and clicking..?

Were you happy with the original color, and now they're yellow? It may just be surface stain, and whitening would help lift the color off the surface. If you were never happy with the color, I agree with the prior answer that 3 years is a long time and you should have mentioned it at the try-in step. The original dentist may be able to redo it for a discount, so I'd try there first. Sincerely,Dr. Reiser

I'm my dental office we replace your crown with no questions if you are unhappy within the first 7 years.if your dentist doesn't follow this policy find a new one.

Since you have been wearing the crowns for 3 years I doubt you will convince the dentist to redo them free of charge.  You definitely should have brought this to your dentists attention a lot sooner if you had an issue. The grating sensation you are feeling could be an unpolished area of the crown after an adjustment was made for your bite.  Having the crown repolished may halo quite a bit with this. If the yellow appearance is to unaesthetic for you to accept them they must be redone.   I would suggest whoever you see allow you to look at the crowns prior to cementation for approval.  This way they can easily have the lab make the necissary changes.