
My opinion is:
If the character creator lets you do it, it's lore-friendly.
So the character creator lets you have dark brown-skinned Keepers of the Moon.
That's lore-friendly. If the developers didn't think characters like that existed in the lore, they'd restrict those skintones away. They've done similar for some of the other sub-races (au ra spring to mind - xaela can't have bright red skin, and raen can't have pure white skin).
If the character creator lets you do it, it's lore-friendly.
So the character creator lets you have dark brown-skinned Keepers of the Moon.
That's lore-friendly. If the developers didn't think characters like that existed in the lore, they'd restrict those skintones away. They've done similar for some of the other sub-races (au ra spring to mind - xaela can't have bright red skin, and raen can't have pure white skin).