Do Pinstripes change colors??

[TheBallPythons]

Since around 3 month my pinstripe is getting more yellow in certain areas, he was fully brown when i got him a year ago...
Is it something normal?did he catch a kind of scale disease??He's healthy and never refused a rat...

[Centexsnakes]

I don't know but am interested cause pinstripe is my fav morph! Very pretty snake by the way!!