The heroes and villains in westerns had reliable looks
In old black & white westerns of the 1920s-40s, the heroes and the outlaws generally followed pretty standard looks. Our heroes would be in white hats, our villains in black hats. This is largely because of Western culture’s semiotic associations that the color white represents good while the color black represents evil. Also, white & black standout more in the colorless mediums of early black & white movies and tv. The show Westworld carried this forward when visitors to the park chose which color hat they wanted, which informed their experience in the park of being a good guy or bad guy. This distinction of white hat or black hat has become a cultural metaphor more broadly. In the hacking community white hat hackers hack ethically in order to find security flaws and work with companies to improve their defenses, while black hats hack to steal information.
Beyond just how they look, some westerns also had the heroes and villains move in certain directions during pivotal scenes. Because most people are right handed, heroes would walk from left to right across the screen with their gun hand visible to the viewer, keeping their intentions known at all times. Villains would approach from right to left, with their gun hand hidden from the viewer, as if hiding their intentions from the audience.
Outside the western
Our association of the color black and villainy extends beyond tv & movies. A study of 25 seasons of NHL hockey found that players wearing black were penalized more frequently than players in lighter colors. Whether the players in black really were more villainous and committed more penalties or that the referees were biased by black clothes, is unclear.
One notable exception with our connotations to the color black of course is the Man In Black, Johnny Cash. Cash sang that he wore black as a visible symbol of his solidarity with the marginalized people who our society has ignored & abandoned.