Following in case someone has a solution to this...I have a Baby Quackers that isn't exactly yellowed, but seems to have a gray, dirty look to her, and I just had the feeling that sun fading would be bad for her. Not sure why some white ponies seem to be made out of different plastic than others. I'm going to try some things, whitening toothpaste, baking soda, oxyclean, etc. and I'll let you know if anything helps.