Answers to Quora Questions by Yair Davidiy (26 September 2017, 6 Tishrei, 5778)
How did the earlier Jews physically look like before the Roman invasion of Israel?
Pictures from Roman times from the region depict individuals some of whom are assumedly Jewish.
We also have references in Talmudic and other sources.
Jews on the whole were of intermediate, i.e. Mediterranean type, appearance. There were some redheads.
Pale skin was considered referable but most were tanned. Some were quite darkish.
Blondes were also present though not typical.
Centuries beforehand the northern Ten Tribes had been exiled and disappeared.
Egyptian depictions plus Biblical indications and Talmudic sources suggest that blonds and redheads may well have been more common among the Ten Tribes.
What the exact proportions were we cannot say.
The genetical potential existed for any of the major types to have become the main one.
There is a phenomenon known as a genetic bottleneck in which a previous minority type becomes the dominant one.