and a walkie with a surveilence earphone. hell, get an actual radio, and you can probably find what channel each department is using. (typically, each group is on their own channel so that people not in that department don't have to pay attention. camera crew asking for new lenses/filters/etc doesn't concern wardrobe. however, camera crew asking grip for additional stands would flip over to grip's channel)
Oh yeah. Walking around a manufacturing plant. Brand-new hi-viz vest over a dress shirt, walk purposefully. "Must be management."
I wasn't management, I was just new on site and had come from a planning meeting, and I was pretty sure the next guy I needed to meet was in the belly of the plant in a location I only had the vaguest idea of, but I knew it was gonna be a long walk.
I ended up walking the length of the place twice (almost a mile) before I decided I'd had enough sightseeing (but what sightseeing it was!) and and actually asked someone, who made a wisecrack about how he helps so many visiting managers in this joint they should make him a manager himself! I decided against correcting him.
Over the coming weeks at that plant, I wore a T-shirt and older hi-viz if I wanted to blend in as a worker, or a button-down shirt and the crisp hi-viz if I wanted to wander. As long as I kept abreast of my assigned duties, nobody sweated the details, and it was better than any museum of science and industry I've ever paid to get into. Had a few more folks make gentle cracks about how I must be a manager of some other group over to see what this group does, I'd ask a few questions and be on my way.
Likewise for jobsites and urbex, I have a hard-hat covered in stickers, and one that's so pristine I keep it in a pillowcase. Perceived wear is an important component of The Look™.
It varies. The more you can look like "the help" the more likely people are to ignore you outright. And the hi-viz + clipboard is a pretty generic "you don't know me, but I'm the help" outfit.
A few years ago I was once briefly directed into the cockpit of a plane to check on its maintenance status while I was boarding a normal coach flight. I was wearing my only clean jacket, a waterproof high viz coat that must be popular with people who work on rainy roads.
Depends: in many places the high-vis hits the “I'm wearing this because the rules say I have to and I'm not important enough to flout them even though they clearly don't matter here” note very well.