u/Additional-Buddy5592

This skull had been painted and not prepped very cleanly. So I went through the process of removing as much paint as possible and then degreasing them. Let it soak for two+ months in soapy water which cleaned up all but this yellow here. It's currently submerged in acetone and has been for over 24hours at this point.

Question is could the yellowing be cause by damage during the poor prepping or does it just need to soak longer? I don't know the whole process it went through before it was given to me. When I decided to remove the paint I did soak it in peroxide for sanitation I had to change it out 3 times because of debris and the peroxide going brown and murky.