Water Cooler Lid

I recently purchased a water cooler lid. The underside is nice and white like it should be but the top of the lid with the blue rings is really yellow. Is there something I can do or use to make this whiter without ruining the lid and the blue on the rings? Thanks for any help you may be able to provide. Thanks Donna

Donna, your lid may have been an early manufactured lid and have been exposed to salt crystals which still lined the kilns from the salt glaze days. If this is the case, there is nothing that can be done to lighten this yellow tint. If your lid had some sort of glaze, paint or varnish applied to it, you may use paint stripper to remove it. Paint stripper will not affect the blue lines or original glaze. Try a small area and see what happens. My thoughts are that your lid was exposed to the salt crystals, but without seeing the lid, I cannot say for sure. Al Kohlman