Most of the redheads in my area have brown or blue eyes.
Green is the oddity.
Mine come from, oddly enough, the Welsh part of the family.
My second and third cousins look like me and I don't particularly look like my parents, who were tall, blue eyed, fair skinned blondes to my short, tawny red & green combo.
Another oddity...I tried to learn Gaelic but the glottal stops were an impediment, as is the rhotic R.
So I tried Welsh.
Easy. I'm apparently P Celtic, not Q. :)
Ahem. Do you 'mind you P's & Q's'?
And, do you know what that is all about.
BTW, the picture you posted of a Neanderthal boy is claimed to be that of a Modern Human/Neanderthal mix.
The Neanderthal Theory
(Lots and lots of info here.)