I've never tried containers but I believe some gardeners do and If my memory serves me at all some gardeners bring them in the house for the winter.
. Containers may give a little head start advantage on soil temperature. From my experience when removing the plants
( California Wonder usually ) in the fall and observing the root system I would think a container of 18-20 inch diameter or more and about that tall would be appropriate.
So I say try a container planting then you'll know what works for you.
To answer your previous ?? about color, I've found some of the bell I plant become red with maturity better than others on the same plant and some varieties may be better at turning red. My wife likes the red too but at my place it's a race for red or let insects have their way. I'm just a country boy gardener and don't know much about those details.
OH, BTW, anyone that likes meat loaf, try some diced bell peppers mixed in for flavor.