Often, this is called fluorescent yellow. But I think it's actually Emergency Vehicle Lime-Yellow. Oh my god, I simply adore the complete artificiality of this color. It's perfectly bizarre and I adore it. When my local Fire Department switched over from red trucks to this fluorescent lime yellow ones, it was jarring. I associate fire trucks with that traditional red. But gosh, how I loved that new crazy glowing lime-yellow! Just YUM. I think they've since transitioned back to red.