I think using inspiration from African ethnic groups would work well for Wild Elves, Copper Elves would probably be more like mixed background people because Copper Elves are exactly that, a mix of Wild Elves and the other Elven types. Greek ethnic inspiration seems like a good fit for Sun Elves IMO. Moon Elves and Star Elves physically are probably the ones to give the more anglo caucasian appearance. If the were to branch out further, I'm not sure about "asian" (which is a very generic term sadly) inspiration for any of them, Eladrin might be an interesting one to consider tying a bit of Japanese influence to, considering their art in Volo's Guide. Drow would potentially fit following the same pattern as Wild Elves, considering their background as the Dark Elves were originally from the same regions as the Green/Wild Elves.

However, with all the above, I think you'd still want to:
  • adjust eyes to be more almond shaped
  • add sharper, more angled, more defined jawline and cheekbones
  • make the nose a little narrower
  • reduce chin width to accent the more angled jawline
  • increase the angle of brows slightly
  • make the face a bit more slender