I actually think elves should be dark skined. They have long limbs and slender bodies. Allens rule says this is a trait of tropical animals. Then you add the long ears with a lot of surface area those likley evolved as a way of termoregulating like those on the fenec fox or similar animals.

So these are clearly adapted to a more tropical enviorment than regular humans. And since skin color is also correlated with latitude you would expect them to be generally darker skined. Except from some outling populations that moved north and adapted to colder climates and agricultural diets outside of the forests.

Dark elves on the other hand. Should be very pale since thay live underground. Think mole rats.