Spot-on! Mavros is the anglo-phonetic version of "
Mauro" which is means Black in Greek. Mauritania,
Maurice, etc, are indeed derived from "mauros". Mauros itself derived from the even more Ancient Greek "amauros" meaning "dim, faint, ambiguous (metaphorically)".
Kara- , which appears as a prefix in some comtemporary Greek surnames, means "black" in Turkish.
While on the subject, its worth noting that Ethiopian "Aithiops" literally means "sun-burnt face" from "aithein" (to burn) and "ops" (face).