I'm working on a mod based in Britain just before the Roman Invasion. The tribes will be split into groups:

Caledonian Tribes
Irish Tribes
Manx Tribes
Welsh Tribes
Southern English Tribes

Could someone tell me generally how the people in these groups differed in appearance, as in hair style etc. I wanted to stick to the RTW System of giving each Barbarian Faction its own hair stile, eg. Gauls with long Ginger hair and Germans with short blonde hair. Any help at all would be great.