The Egyptian pharaoh(s?) Sesostris had settlements along the east end of the Black Sea around 2,000 BC. There are apparently some people still living there with dark curly hair and/or? skin which might be descendents.
Herodotus refers to the people of Colchis as being Egyptian colonists, left behind when a pharaoh he (and probably Greeks in general) called Sesostris; the Wikipedia page on this is brief, but thorough and useful, although it doesn’t go far enough IHMO regarding the likely conflation of different eras and pharaohs. Herodotus is known to have been a faithful recorder of what he was told, so the fault lies either in translation or in the account itself.
Egyptians of all ancient periods appear to have had no more competence regarding prior eras than people anywhere did. They did however have some continuity due to monumental inscriptions and a long-lived system of hieroglyphic writing.
The Colchians — who are also said to have practiced circumcision — referred to there were probably either descendants of the Ten Lost Tribes exiled by the Assyrians (the Assyrians had a presence of some kind in the Crimea for example, and the exiles were scattered to the frontiers, including Central Asia, where three of Ashoka’s pillars are written in Aramaic) or less possibly descendants of Egyptian allies of the Trojans during the Trojan War.