Won a signed Jersey - off colored jersey numbers?

I won a Josh Allen signed jersey today at the SPCA event and when I got home I realized that the 7 that is signed is a little off white, whereas the 1 is white. The two numbers are different colors on the back.

It came with a certificate of authenticity, and it came from the SPCA event, so I doubt they'd have a fake, right?

Does anyone know if the numbers on a signed jersey can be different colors? I am wondering if they have Josh sign the number seven parch and then attach it later to a jersey specifically made for these events, hence the off white seven and a perfectly white one...