At a company where I worked, red badges indicated someone was a contractor. Everyone else had a white badge (sometimes with a colored marker for certain kinds of access).

"Red badges" were routinely made fun of and hazed. A pretty high percentage would end up getting hired full-time and the hazing would stop, so it wasn't exactly "personal", but it was definitely kind of weird.

(I have no clue what a red badge indicates at Amazon, though.)