it's not mouth rot. but thanks for you concern (he was eating when i took the pic that part of a mouse) but i check all my snakes & lizards every week to every other week

I know what a Pastel looks like & he is that color it didnt show in the pics, But the part that looks "paradox" is from his head to a bout a 1/3 of his body is a high yellow normal then like 5-6in of the "pastel" yellow the like 1-2in of the normal then like 4-5in of the pastel then 2-3in of normal then the pastel to his tail (even if it's not and i was lied to i dont care he's a great snake but in person looks like no other normal i've seen)

I'll get new pics, but he is starting to shed so the yellow looks like a white yellow, but i'll add pics

But in this pics the red outlines are the "normal" and the green are the bright yellow parts

And about the belly it's white & black, but parts have a li'l yellow to it