Bred 4 Midsole Paint Removal Help

Hello, when I was removing the midsole paint from my bred 4s I noticed that underneath the black paint was some white paint and under that was the plain midsole (I believe it's the plain midsole). I was wonder if I am damaging my 4s or if this is natural but for now I just stopped until I get further information. To remove the paint I was using nail polish remover. If you have any information please help and thank you.