The bulk of modern Europe was covered in thick glacial ice, when it receded the "first Europeans" walked in from the south.

A number got a lot paler after many generations in the more northern parts, others less pale, and those near the Mediterranean were neither ghost white nor midnight black.

Now throw in a steady low rate of long distance trade - traders travelled, as did those enslaved and traded.

The Roman settlements in England were mainly established by people not from modern Italy, they came from across a broad part of the full Roman Empire, one fort was manned by Africans.

So - legitimately mostly white skinned people with a small percentage of every other shade. Depending very much which bit of "Europe" you're looking at.