Genetic ethnicity varieties
There's a few missing here that can't be replaced.

This is probably in part going to give my character away but I didn't know how else to write this.

An example would be, if you chose to play Cornish or Welsh, you would have to go with 'English' as the closest ethnical variant. But neither English, Scottish or Irish is close enough. 'British' would be acceptable, as the Welsh and Cornish are Brittonic celts.

If you don't think they are actually different, then you should do some research. The Brittonic celts are known for being dark haired and fair skinned. While the Irish and Scottish vary as well, they have more redhaired genes than the Welsh and Cornish. Meanwhile, the English are usually more lighthaired, though I believe they have somewhat blended with the Brittonic celtic natives of the area.

There are already quite a few disputable genetic ethnicities in the game, unless you count cultural. Some are simply cultural ethnicities, for instance Turkish, a people that is never quite defined and vary depending on where they inhabit (due to their historically nomadic culture).

Back to the point: Any genetic ethnicities you want to see? Post them here!

I agree with Reefer, it seems like an unnecessary system now that corpses show @nakeds.

Completely custom ethnicity I think would be nice. It doesn't really make sense that forensics can tell what race you are from your corpse so maybe those characteristics could be scrubbed on death too. Leave it to the player to (tastefully) put nods to their ethnicity in their @nakeds if they wanted to leave a clue.