I can answer my own question, for anyone else who's curious, but I warn you it's not worth the faff.Is it possible to spawn a random character of a given culture with a pre-defined hair colour?
I've seen probability breakdowns for blonde/brown/red hair in culture definitions, and I know a unique appearance would include hair colour, but for a random shmoe created by an event, is it possible to simply define you want the created character to be eg a ginger?
The same probability breakdown as in the cultural definition files are in the save game data. Here's the surrounding section from the record for 185/"english", with the default values in the ethnicities line. If you're desperate for a redhead or a blonde before you search for knights, you can edit the probabilities here to make the preferred colour 100% and the others zero and it seems to work. I've got a lot of patience for wasting my time doing some tedious save scumming, and I like to have a control freak level input in my virtual eugenics, but honestly this works out about as slow as just editing the character's DNA string in the debug console's portrait editor... and you don't even need to re-edit / re-load to return to the default ethnicity values after...
Code:
name="english"
color=rgb { 204 51 51 }
collective_noun="english_collective_noun"
prefix="english_prefix"
name_list=name_list_english created=1070.1.1
ethnicities={ 25=caucasian_blond 15=caucasian_ginger 35=caucasian_brown_hair 25=caucasian_dark_hair }
building_gfx={ "western_building_gfx" }
clothing_gfx={ "western_clothing_gfx" }
unit_gfx={ "western_unit_gfx" }
coa_gfx={ "english_coa_gfx" "western_coa_gfx" }
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