Pricked them out into individual 3" pots today.
They're 'Numex Twilight' -- usually grown as an ornamental as you get lots of small chillies which ripen at different rates, so are different colours. I think some of them end up purplish but I'm not sure as it's a few years since I've grown them. They are perfectly edible and, as we don't go overboard on chilli, the fact they're not the hottest you can buy isn't a problem.