Bell peppers of any color can be eaten green. They won't taste as good but it's how I compete with bugs and scavengers. Red and yellow bells cost more for a reason- they seem to take forever to color up. I grew purple peppers last year, yummy but so dark..almost black, most got sunburned on one side.
This year I am focusing more on bells, and poblanos, Anaheim. Last year was all about the super hots, but I gave up the ghosts. I just got my seeds started this week, will have them in the greenhouse until at least April.
My wife complained that I was running her out of the upstairs with one small orange habenaro pepper! I enjoy peppers though and it amused me that one small pepper the size of my thumb could cause so much grumping!