I just want to say that while this is representative of what some bodybuilders do. It's also completely wrong and not representative of how you can diet for a competition.
Modern bodybuilding is not "witch" magic. You count calories, macros, and your exercise output and manipulate those to lose weight. Anyone who is saying one bell pepper type is okay but another isn't doesn't know what they are doing, and it's not fair to judge bodybuilding based on that.