It would have made more sense to show him getting greyer as time went on, since it would then line up with Vader’s face too as they were both dark side users. Didn’t he look worse in AOTC than ROTS? It’s a redundant rebate I suppose.
He totally did.
AOTC
ROTS
I guess they were originally going for him to look more and more corrupted over time.
Never heard of the EMPEROR PALPATINE SURGICAL RECONSTRUCTION CENTER?
http://starwars.wikia.com/wiki/Emperor_Palpatine_Surgical_Reconstruction_Center
😉