I've checked, and we don't have this yet. Other tropes are close, but are not specifically this. And before anyone thinks this is too common, No Trope Is Too Common.Rolling Updates
Black is perhaps the most typical color for evil, or at least the antagonists, to wear. Thus in many stories, the villains will wear largely black clothing most of the time, in contrast to the colors worn by neutral and good characters (which will be at least moderately lighter).
This is because in many cultures, black is the color of darkness, decay, and death. Thus even though wearing black doesn't make someone evil, being evil makes it more than likely one is going to wear black.
It doesn't matter if it's all the villains, the Big Bad and a few others, or just a group of Mooks that appear for a few episodes, if they wear a large amount of black (even just one noticeable part of their clothing), you know it's this trope. This is also why black is a common color for an Evil Costume Switch.
Heck, some Eviler Than Thou villains might wear black when the "lesser" evils don't.
There's some science behind this. There are studies that show that people that wear black are more aggressive than people who don't. They've also found that black isn't only associated with evil, but also contamination and sickness. These associations give people an instinctive cue that the person wearing black is dominant, and somebody you don't want to mess with.
Now since some think Evil Is Cool, then black can also become a cool color, but those don't cover this trope, nor does this trope come into play if the heroes also wear black. This can come into play with a Villain Protagonist though.
Zig-Zagged in Lyrical Nanoha: in the original incarnation of the series, Chrono Harlaown was the bad guy and wore black clothes with Spikes of Doom. As the concept of the series evolved, Chrono became an interdimensional law officer but kept his black attire, which was instead retrofitted as the uniform of the Enforcers, top-ranked dimensional police. Fate Testarossa took Chrono's place as the main character's rival and resident Dark Magical Girl and also wore black from the onset, but the series went the Dark Is Not Evil route, and Fate turned out to be the most Lawful Good character in the show, while still wearing mostly black because it suited her--and because she eventually rose up to join the ranks of the Enforcers, just like Chrono.
Winnowill from ElfQuest wears a black dress (trimmed with white fur) most of the time in her initial appearances and tops that off by having long, black hair. Even the warning nickname later given to her, "The Black Snake", contains the color and her harmful magic is referred to as "Black Sending".
Black Adam, Shazam's archenemy, predominantly wears a black and yellow uniform.
Film - Animated
Maleficent, the evil fairy of Sleeping Beauty, wears a long black cloak with black horns. She even calls herself the "Mistress of all evil".
Willow: All of Bavmorda's men wear black armour. General Kael complements his with a scary bone mask.
In all Winnetoufilm-of-the-book movies. Winnetou wears beige clothes with blue ornaments and Old Shatterhand wears light brown clothes. All the bandits wear very dark clothes, and one item is usually black, be it a hat, trousers or a shirt. The main antagonist tends to have a completely black outfit in each part of the movie series, though perhaps not for all his scenes. In Winnetou I, Old Shatterhand and Winnetou are not friends yet and Old Shatterhand has to fight with the Apaches. He wears a sky blue shirt, and his friends sport bright colours as well. It was crystal clear he's a good guy, and not only because it's a prequal to Treasure of Silver Lake and everybody in Germany and Eastern Europe knows that those two pals are Heterosexual Life-Partners.
In The Wizard of Oz the Wicked Witch of the West wears black. This is in contrast to Glinda the "good" witch we meet who wears pink.
In the comedy The Villain, the eponymous villain wears black.
In Shadows of Freedom, one (solarian) character is somewhat amused by the tendency of repressive dictatorships to outfit their jackbooted thugs in all black uniforms. This is also a bit of Hypocritical Humor, since the Solarian League's own jackbooted enforcers, the Gendarmerie, wear black uniforms too.
When Xander and Willow become vampires in Wish!verse, they wear black leather. When the real Willow pretends to be vampire!Willow she steals the latter's black clothes.
Doctor Who Classic: the Master as portrayed by Roger Delgado and Anthony Ainsley wear all-black unless he's in disguise.
The Peacekeepers from Farscape wear black armour or uniform. The villain Scorpius is dressed all in black, as well.
Ares from Hercules The Legendary Journeys favors a black leather get-up. Similarly, any and all servants of Hera are most likely wearing black leather and skull-motif armor.
Rufus in House of Anubis wears the same black coat, black turtle neck and black pants in virtually all his appearances.
From Once Upon a Time: Black features prominently◊ in the Evil Queen's wardrobe. After her Storybrooke counterpart Regina tries to redeem herself to its citizens, this is reflected in her wardrobe changes: she wears more gray shades and more color.
While he didn't always wear black, Doctor Steel did on occasion wear a black PVC outfit with top hat and cape.
Warhammer 40,000 has the Black Legion, arguably the most powerful and evil Chaos Space Marine Legion whose color of choice is written on their name.
Some of the playable characters in Death Smiles are, or used to be, evil, such as Casper and Sakura, who both wear black outfits.
Fallout 3, the evil mercenary armies of Talon Company wear a custom variant of Combat Armor painted black.
Kingdom Hearts, Master Xehanort's clothing is primarily black and grey, while the members of the Organization wear black cloaks.
Pokémon, Team Rocket's members wear black with red "R" emblems, while Giovanni is depicted in the games wearing black suits. In the anime he wore orange at first, but switched to black in Best Wishes when he and Team Rocket became major antagonists again.
James and Jessie, two of the main antagonists of the anime adaptation, wore white uniforms and were mostly used as comical relief in the seasons before Best Wishes season. In that season, they get noticeably more competent and evil, and of course, they switch to black clothing. When they switched back to their regular white-and-red uniforms, they get noticeably less competent.
Albert Wesker from Resident Evil, while not this trope normally, starts embracing it in the fifth installment - with a longcoat made of pure black leather, as well as black inner getups, gloves and boots. The only thing that isn't black would be his hair and his eyes.
In Street Fighter, Akuma by default wears either a black or dark purple gi. When Ryu becomes Evil Ryu, he's also depicted with a black gi (which becomes tattered in the fourth installment). M. Bison also wears a black cloak over his red outfit, although he tosses it off when the matches begin.
Richard of Looking for Group is one of the protagonists, but he's also an undead sorcerer who actually needs to do evil acts to maintain his powers. He wears a black robe and hood.
Five hats means that five tropers think it is ready to publish.
You are saying that you think this draft is ready to be published. That means the description is not ambiguous,
it doesn't duplicate an existing trope, there are at least three examples, and the title makes sense.
Is that what you meant to do?
You are saying this draft has a ready-to-publish hat it does not deserve and you are taking it back.