I don't give a flying fuck what color skin the ponies have, so long as they look good and keep with their personalities. You captured Luna's spirit and longing perfectly with this, and it just so happens that she's dark skinned. Woohoo I don't care. Look at her. She's gorgeous and you did a brilliant job of matching the colors, though I feel that her eyes pop a bit more than her hair, which could've had some more variations of blue. That's just me though