It happened with two ponies I have a Steamer and a G3 minty were I used really hot water and noticed the water in the sink turning pink...made me worried about hot water on fading pink at all, so I use luke-warm or cool water on them. I am glad to hear that is not common though so maybe it just happened to be an issue with just those two...Thanks for letting me know that, lol, now I don't have to be so edgy about it!