If you want to say, "I have black hair" can you say, "Tengo pelo negro?"
I have been taught that you can say, "Soy rubia" for "I'm blonde" or "Soy morena" for "I'm brunnette." But can you say "Soy negra" to say "I'm black haired?" I'm thinking the answer is no. If you have dark hair in general do you say, "Soy morena?"
soy de pelo negro es otra forma de decirlo.
Just to mention it, we had a previous thread mentioning in some regions pelo was used for body hair and cabello was used for hair on your head, even though, I think pelo is synonymous for cabello in most places.
"Soy negra" means, I am a negro or dark-skinned.