I can't stomach nato either, roadfix.
I won't eat anything blue, and when it comes to icing I won't eat blue, green, red or black icing. Blech. Especially red. Too bitter.
Most other foods that I won't eat are only because they give me GI distress. I'm pretty good about trying everything at least once. I've watched Zimmern and usually say, "Yeah. I'd try that." I'd draw the line at rotting meat, though. The smell makes me gag.