I noticed similar scene-by-scene inconsistencies with other characters too, maybe just a bad make-up person/crew?

There's a scene where he goes into the elevator and looks like yer man Fisher Stevens in Short Circuit.

I had a very similar color when I returned home from a trip in the very sunny Dominican Republic. Couple of things to consider: that he is a well traveled man and could have been at a tennis match somewhere very hot and sunny, or maybe they sprayed some of that Pamela Anderson goop on him - to add a little variety to the Sam character. I personally loved the little wave and that extra sprinkling of shimmering gray he had mixed in his hair. His appearance seemed to be a bit 'high end Wall Street', perhaps? I adore the man and thought he looked wonderful.