It depends. There are cape verdeans who are heavily mixed or even more European than African, but I'd say the majority of Cape Verdeans are black like me. The thing is that even though Cape Verde is a small archipelago there can be great differences between the degree of admixture of the population of each island. Most Cape Verdean Americans seem to come from the islands with the highest European admixture but they're actually not the majority in Cape Verde, the main and biggest Cape Verde island has a population with around 75% African ancestry on average in fact, kinda like most Caribbean islands.
Amber Rose is only a quarter cape verdeans to begin with so she's not even black by any standards.