My beardy is nearly 3 and the past few days the top of his head is staying a white sort of colour even when the rest of his body goes dark, usually it changes dark with the rest of his body.
Hmm. Looks to me like he's getting ready to shed that area. My beardie had a shed that looked like that (in that area - not quite so white like that) and it took a little while before he shed it off. You sure he's not getting ready to shed? Dunno, maybe someone else here might know more than I do...
This is exactly how Izzy's head looks right before and during a shed. He has gone thru 2 sheds in the last 4 months (He's 7 1/2 months and growing like a weed!) and his head always looks very white like that just before. As a matter of fact he is shedding again now as we speak and I noticed this morning that his head must be ready to go next, 'cuz it's really white like the other times. His tummy and tail shed over the last 4 days. And last week I helped him get some skin off that was shedding from his chin and cheeks. He had been frantically trying to get the pieces off by rubbing his face against his log.