Just did some research on the yellow belly stuff. I found that the lesser yellowbelly looks quite alike to my girl.
This is the lesser yellowbelly with the sparkles you mentioned on the alien heads.
These are the belly shot of my girl. Do you guys think she has yellowbelly? Without the head stamp, I still think she is just a light butter. Also, the pet shop could not trace the parents of my snake.
If the mystery gene is there and it is yellowbelly there may be no for sure way to tell other than breeding it to something like an ivory. Yellowbelly can enhance a lot of stuff but it would take a far better eye than mine to positively pick it out of certain combos.