They literally only have access to High Elf skin and blue eyes, like Alleria, the first Void Elf. High Elf Wayfarers and Darkfallen who were not transformed like Umbric’s Blood Elves also joined the Ren’dorei. The Ren’dorei at this point are a mix of biologically changed Void Elves and High Elves & Darkfallen who have not gone through the same thing Umbric’s Blood Elves did, but are learning and embracing the Void. These High Elves and Darkfallen rename themselves Void Elves, or Children of the Void, but have not been shown to go through the same magical, cosmic change that Umbric’s Elves did in the questing. I’m assuming Midnight will flesh this whole thing out more, but that’s where the lore is at right now from my understanding.