Your snake looks like it shed recently...(well, that's my completely neophyte opinion...); when Fritz sheds, for the first few days afterward, he also has the same kind of "holographic" sheen to his head...and then it seems to fade. Sorry for the Vanna-hand-pose (I really have no place to let the snakes have a controlled roaming place for photos...I also really need to move to gain more space!), but this is Fritz recently, in a very plain environment with white lighting...
(I actually was trying to take this side-view kind of photo, though, to be able to really see how the yellow is growing not only brighter but lengthening with his body as he's growing, and because of the rose-colored splot right behind his eyes. I was surprised, because even my 2nd graders noticed it, too...Fritz not only seems to be getting paler & paler, but also more yellow-y...ahh, the wonders of genetics...
)