I believe the Red haired ones are predecessors to the blonde haired ones.. ( recessive genes causing the blonde hair )
The red hair characteristic is found a little more in certain areas of europe like Germany, and of course, Ireland and Northern England..
It tends to be a little less in the Scandinavian nations, where the blond hair is more prevalent..but I would guess that red hair occurs there more often than not..
From what little archaological evidence we have so far, I would think that red hair was predominant among the "proto-celts", with the occassional blonde, definitely aryan, not meditteranean... ( typical roman - greek - egyptian? )
Possibly "Aegean" would be a more apt description..of the original peoples of the meditteranean basin.....
I recall reading somewhere, (long ago) that they were originally olive skinned, almond eyed, black hair, well proportioned, but not very tall..
It was theorized that the modern meditteranean people is the result of the meeting of "northern" invaders, settlers, population influxes, however one wants to describe it..
Having seen pictures of the murals at Minos and Acriterae (sp?) I believe this to be an accurate depiction..
Incidentally, this falls into line with the description of certain characteristics of both asians and polynesians as well, with the possible exception of actual skin tone..
That would be explained both by both the mixing of original proto-celts, original mongoloids, ( so-called "red" skinned, ancestors to American Indians ) and possibly another group.. the Aegeans, which may be descended from that first civilisation you have conjectured about that left what is now Indonesia at the end of the Ice Age..
This is the stuff that has always fascinated me about archeology and anthropology..
The initial movements and migrations of these various groups of mankind..
Blame Robert E. Howard.. He's the one that piqued my interest in this sort of stuff..