This is my first time posting on this stack, so excuse any ignorance! I have been growing Espelette Peppers in Paris (France) under a grow light during the colder days and hardening them off to our sun-baked south facing terrace. It’s been slow growing, but one plant did particularly well under my inexperienced guidance. However, it now has a sort of purple rash on it’s leaves. I’ve googled and googled and googled, but so far nothing.
Anyone have an idea of what I’m looking at? Or how I might treat it?