Of course, part of the creepiness comes the fact that the 1968 version of 1967 Barnabas has enough eye make-up to sink a battleship, whereas in 1967 they were doing their best to make Barnabas look like an ordinary human being.
Though believe it or not they sometimes use the same sort of heavy eye makeup in 1967 when Barnabas is in full-on vamp mode. One ep that comes to mind is Ep #230, which, perhaps not coincidentally also takes place in the cemetery/mausoleum just as Ep #588 does:
Ep #230
Ep #588
Also, the makeup for Ep #248, in which the flashback scene from Ep #588 originally took place, is similar (at least with the dark lines from the corner of Barn's eye and along his undereye):
Ep #248
What is really odd is that they go back to the heavy eye makeup during Barn's Pepe Le Pu phase of Leviathans, yet no one ever mentions the change in his appearance. I guess anyone who isn't in the know and[spoiler]isn't aware that he's become a vampire again[/spoiler]just figures he's experimenting with eye makeup and strange highlights, but they're too polite to draw attention to it by talking/asking about it.