The Romans surely met peoples of different skin color in their interactions between Gauls and Africans and many others. I assume that there were clear color differences back then and that the Romans noticed it. What adjectives did they use to describe those colors?
The typical words in modern English to describe the difference between the most common European and African skin colors are "white" and "black". These are not very accurate descriptions of the colors themselves — perhaps "pink" and "dark brown" might be closer — but they seem to be somewhat abstract and focus only on the difference of color. It is not clear that the Romans would approach this the same way nor that they would have a canonical choice of words of any kind, but I would be surprised if the difference was never observed in the extant literature.
This question is not about white and black skin but variation in skin color in general. I merely wanted to provide two English adjectives used to describe the differences in skin color of the people that inhabit today the area the Romans knew.