back in them days of yore... (repetition for phill)
doing a poster with color on it was considered 'pussy' or 'sell out'. it could actually hurt the turnout if people thought you had money behind you. if you did a BIG poster with color and all, people would accuse you of going 'new wave' and selling out totally. they'd shun you as fakes.
so, doing big color posters were a non-starter. the only real time you saw it was when a 'professional graphic designer' did the poster (they didn't understand what they were doing) or some little record company did a color poster to promote a record - because that was the way promo posters looked. they were sort of following the language as they tried to figger it out. the only way you could afford a color poster was to silkscreen it yourself. so, that's where many of the early color pieces originated.
the crappy little xerox poster was a real poke in the eye to this city (seattle) because there was a widespread very beautiful and colorful poster scene already existing. great posters were everywhere. so, punks worked with what they had (nothing) and could afford (below cheap). so, they created a language that spoke from telephone poles and was was ignored by the (then) preppies and the software swine. even mainstream rock people ignored them. it was the only way they had to talk to each other in the city.
so, to dis a flyer as less than a poster is incorrect. they were more powerful than posters. they were superposters. and they didn't need no stinkin' capes.
i guess the point is that the only difference between a "flyer" and a "poster" in the current definition of things is size. and i think that's pretty arbitrary, pointless and more than a little elitist. it's used to dismiss 'flyers' as vaguely unworthy of merit next to a "real poster".
there was no difference between a flyer and a poster. however, a handbill is something distributed in your hand. a poster was posted. that was the only distinction. we only started calling them flyers very very very recently (like maybe this website changed that all by itself). i think it was done to make everybody think they were doing something special and more important like an artistic poster and that it is inherently better than a (mere, lesser, inferior) flyer. but, i think that elitist position is BS.