So a few weeks ago, I planted some "Purple tiger" (a.k.a. Trifetti) chilli seeds I got from a friend - some in the sunroom, some in the courtyard. Turns out the sunroom worked well as a greenhouse. 5/7 came up there, as opposed to the courtyard where 0/8 came up.
They look like this now:
You can see the purple tinge in the leaves. They won't be very hot as chillis but they should make a decorative plant as well as a milder chilli option.