The purple streaks on the banana and Hungarian sweet or hot peppers is perfectly normal.

Wow, I've just had so many of these and this is the first color change...weird.

Thanks!

Normal coloration that can happen when they grow past maturity. I see tinges of purple on many of my ligher green peppers too.

Ken, The peppers do not have to be mature to have the purple streaks. I sell all types of peppers at the Farmer's Market, hybrids as well as open-pollinated Hungarians, Jalapenos, Cubanelles. You name it, I probably sell it. Weather conditions as well as temperature can have a huge effect on the ripening.

I only see it here on bigger mature pepperoncini, so it I guess it can very with the pepper types.