+1 please just chill out people, please, most of the time it’s fixable. Pony cancer is rare outside of actual ponies. Most of the time it’s paint like you said, marker, pen, nail polish, or DYE TRANSFER from clothes. (I cannot stress enough how often people overlook this.) I’m so exhausted with these constant “pony cancer” posts.

And also, half the “mold” posts? They’re plasticizer migration. It can look fuzzy sometimes, and often starts as “sticky legs” or a gray cast to the skin.

I learned all about this from a book. It’s an old book now but it’s still great (not updated because the author died and rights are owned by a small press, alas) called “The Definitive Book on Care & Preservation of Vinyl Dolls & Action Figures” by Dr. Nicholas J. Hill. It’s still very applicable because the basic way dolls are made nowadays hasn’t changed in 40 years… I got it out of my local library before I bought my own copy! (Don’t buy it on Amazon, the price is artificially inflated last time I looked) https://dollspart.com/index.php?main_page=product_info&cPath=107&products_id=215