I would like to put this out there. No matter what skin colour you have, you can cosplay whatever you wish!
You should have the confidence to cosplay a character no matter what skin type they have or you have. I’ve seen so many different cosplays of every colour! Also i’ve seen a dark skinned sailor moon, and to make the look more natural for her, used black hair.
An amazing cosplay blog would be here http://cosplayingwhileblack.tumblr.com/
Cosplayingwhileblack is an amazing blog that shares amazing cosplays, also share characters with darker skin that you could possibly cosplay as well! great blog!