Ever heard of the term “genetic admixture” and population dispersion / cultural assimilation?
Let’s disregard Herodotus’ description of Colchians for now since it’s disputed.
Here is an example of an ethically African population living in present-day Eastern Europe: https://en.wikipedia.org/wiki/Afro-Abkhazians
Not to mention all the ethnic groups displaced during the population exchange during the Greco-Turkish war in the 1920s.