Help with ancestry question?

Ok my mom said that we might have African ancestry cuz my grandmas grandpa had African characteristics. We r Mexican. Although I was born here. And I have tan looking skin. Not too brown but in the middle of dark and white. My brother and sister are lighter skinned. Me and my mom are darker skinned. And my dad is lighter skinned. I think one time he said we jad Spanish ancestry but idk. So what does that make me?? ( ex: Mexican- American( something likethat)