I was at the grocery story earlier and once again, my curiosity kicked in. So I decided to post the following on Facebook...
"Someone please explain to me why green bell peppers are only $1.99 and the red, orange and yellow ones are $3.99 :/ They don't taste different. I'm so confused. This is why I stay away from the kitchen."
Here is the best answer: Maturity, it's the same pepper but yellow & red are left longer before harvested. Red are more sweet.
My first theory was because the price of food colouring went up. But I was definitely wrong!! Shout out to my awesome friend Noel and his wife for it.