when the romans started off, they would have looked more like modern day swiss or austrians than modern day italians. the italic languages are thought to have evolved alongside the celtic languages in modern day switzerland, before moving south into italy. but celtic and italic actually are thought to have split rather late, so the wide swath of western europe including spain, france, southern germany, italy and the british isles would have emerged from the bronze age roughly homogeneous in culture and language.

over time, the pax romana, which set in after augustus, led to large scale migration all over the place. the romans also brought in massive numbers of slaves from everywhere they conquered, and freed a large number of them in the end. genetic studies have demonstrated a major footprint from the orontes, which was noted in the classical literature as well.

so, rome changed over time. but, for the proper roman period, ending in 476, the emperors would have mostly been startlingly, pasty white.

if you want to know what a roman proper looked like, zuckerberg is actually pretty much spot on.

https://www.quora.com/Were-Roman-emperors-all-white