I got this nice glass piece about a good 2-3 months ago and the paint has begun to peel on the inside of it. I thought the colours were inside the actual glass itself, whats going on?

First pic is before paint was peeling, second and third are after.
GreenGiant07 Reviewed by GreenGiant07 on . Paint job on my pipe I got this nice glass piece about a good 2-3 months ago and the paint has begun to peel on the inside of it. I thought the colours were inside the actual glass itself, whats going on? First pic is before paint was peeling, second and third are after. Rating: 5