if you're asking.
the answer is neither, and both. it's such a complicated question that you can't really answer it.
the thing people lose track of when they ask this question is the sheer amount of time that we're talking about. "ancient egypt" as we understand it ended with the persian invasion, about -525 (people will throw around other dates, but the persian occupation was the one that egypt never recovered from, passing into the greek and then roman, and then arabic, worlds as a province of a greater nation, rather than it's own thing). the first dynasty (that we know of) takes you back through 2500 years of sketchy history, and it's thought there was at least that much time in egyptian pre-history.
so, we're talking about thousands of years here - enough time that a transit point like egypt, at the intersection point of three continents, would have experienced several waves of population replacement.
as far as anybody can tell, the earliest egyptians came from the south and would have been black. so, when you hear people talk about the oldest egyptians, the ones that first settled in the region, the ones that built the first granaries and the earliest civilization, the general understanding is that these people would have been similar to the modern sudanese, and would have migrated into the region from ethiopia, first setling in the nile river valley, before moving up the river towards the mouth and eventually settling along the mediterranean.
but, these would have been black tribes moving into a white world, and it wouldn't have taken long before they came into contact with libyans to their west, with sumerians to their east and with old europeans (pelasgians?) to their north, all of whom would have been caucasians. and, over time, the initially black egyptians bred with the white people that surrounded them, creating a hybrid breed that formed the basis of what we today understand as classical egyptian civilization.
even the middle period egyptians themselves recognized the existence of africoid black people, but othered them as "kushites" and "nubians" and placed them to their south. they were aware of black-skinned human beings, and explicitly did not identify themselves as such.
to be pseudo-scientific, it's interesting to point out that the oldest points of human civilization all occurred not in places where one race was dominant over the others but in places where races interbred - that is the commonality we see on the yangtze, on the indus, on the euphrates and on the nile. places where races were isolated - like subsaharan africa or northern europe - took longer to develop into advanced societies. is the lesson, then, that humans experience a type of hybrid vigour, and that maximizing gene flow is good for stimulating innovation? i'm not taking that leap, but i'm comfortable stating that i've wondered about it, and wouldn't be surprised if the science upholds the point in the end.
on top of that, the evidence seems to suggest that, while race-based slavery did exist in egypt, it was variable and overturned depending on which group was more powerful at whatever given time.
so it's a very difficult to define question, and it may be missing the point; what made egypt what it was was that it was a melting pot, a place where white & black met as north & south and transformed into something unique.
so, you'll see white egyptians & you'll see black egyptians & you'll see egyptians in between. they're all correct.