Question of the Day: What are green bell peppers?
Quick Answer: Green bell peppers are, in most cases, the unripened fruit from the Capsicum annuum plant, but not always.
Most varieties of capsicum progress from green to yellow and then, when fully matured on the vine, turn red. Others turn yellow when fully ripe. A third group, smaller still, starts out green and stays that way.
Taste is the easiest way to determine if the green bell peppers you are eating are immature. All bell peppers have a bitter edge when younger and slowly grow sweeter as they fully develop.
If your green bell peppers are sweet, then they happen to be the fully ripened fruit of a variety that stays green. If not, then they are juvenile bell peppers.