It is almost inevitable that whenever you see a bull in frame, sooner or later that bull will see red. Almost always, this bull will see it on the person of the protagonist. And absolutely always, the mere sight of red will drive the bull into a frenzy. No exceptions. Bull sees red, you better start runnin'.
This is more popular in cartoons where the bull's emotions and behaviours can be drawn (gusts of breath snorted from the nose, red filling up the eyes etc.) and you don't have to pay for the pleasure of an irritated bull in your studio.
This idea was started by bullfights in Spain, Mexico, and other Spanish-speaking countries, where a matador would wave a large red cape to get a bull to charge at him. In real life, it's not the color of the cape the matador's waving that makes the bull charge; it's the fact that the matador is waving the cape at all. In fact, the cape being universally portrayed as red in the first place is actually a Dead Horse Trope by itself: modern bullfighting is mostly done with a fuchsia and yellow cape (called capote), and they only switch to a red one (called muleta) for the last third of the round.
The fact that the color is irrelevant was proven long before the MythBusters tackled it on their show. Characters may also occasionally mention that bulls are colorblind, but this is also untrue (though the range of colors they can see is narrower than a human's). As this awareness has grown over time, expect to see many deconstructions and aversions, with the characters pointing out these significant bits of information.
The actual reason for the use of reddish/pinkish colors in Real Life bullfighting is to mask the bull's blood, as covered by Bring My Red Jacket, for the benefit of the audience (bright red really catches the eye compared to, say, navy blue), and for the psychological effect (red being more exciting to look at versus, say, pastel green). See also Red Is Violent and Brutish Bulls.
- Lampshaded in a Russian ad, where a guy ends up in inside a fence with a bull. One of his friends shouts from outside he's wearing red. The guy covers himself with mud... and then another one of the friends remarks "Aren't bulls color blind"?
- In a case of this trope applied to what used to be a steer, a restaurant customer in a Tums antacid commercial uses a red cloth to deflect the attack of a giant animated steak that's symbolic of heartburn.
- Hols the Bull in Juuni Senshi Bakuretsu Eto Ranger uses the color red as his Transformation Trinket; whenever he's looking at it, he's able to transform from an anthropomorphic bull into a much stronger realistic one.
- An episode of Naruto has our hero procure a ride on a bull, though the bull seems less interested in letting him ride than chasing that big, bright red spot on the back of his jacket. Enter two more bulls, and Naruto has a free run to wherever he wants to go (as long as he's doin' it on foot).
- Despite not actually using bulls, an early episode of Pokémon still invokes the spirit of this trope. Scyther and Electabuzz are both said to fly into a berserk rage at the sight of the color red. It just so happens that Pikachu had discovered a love for ketchup in that same episode, so during a showdown between two rival gangs whose leaders used a Scyther and Electabuzz, a stray attack splits Pikachu's ketchup bottle open, splashing the stuff across both combatants' eyes. Since everything they see is now tinted red, they promptly start attacking everything in sight (including their trainers).
- In one episode of Revolutionary Girl Utena, shortly after Nanami turns into a cow after wearing a cowbell for several days, Anthy finishes the sweater she had been knitting the entire episode and gives it to Utena. A red sweater. Which results in Cow!Nanami becoming enraged and Utena using the sweater as a bullfighter's cape.
- In the Motu Patlu episode "Bull Power", Dr. Jhatka creates a drink that causes whoever consumes it to become as powerful as a bull. Ghasitaram suggests he give the drink to Patlu, who starts to chase anything he sees that is colored red after drinking it.
- In one Archie Comics story taking place at a rodeo, a bull escapes from his pen and it looks like he's about to hurt the cowgirls — but then it sees Archie's red hair and goes after him. Afterwards, Archie is applauded for "distracting" the bull.
- The same happens in a Donald Duck comic story, "The colorblind bull", where Grandma Coot has a - yeah, and said bull starts rampaging at the sight of anything that's light blue. The real disaster happened after the bull won the blue ribbon at a fair, and Donald (who still didn't understand what the problem was) got the bright idea of sticking the ribbon to the bull's forehead...
- Green Lantern #52 reveals that the Rage Entity is a red bull.
- Howard the Duck runs into an idiot in a bull costume who claims that his enemy is the color red when the two of them are standing in line to register with the government during Howard's Civil War tie-in. Howard distracts him by claiming to have seen "something red down that hall", which causes him to go charging off to destroy it. When Howard meets him again on the way out, he directs him to head for the Obstructive Bureaucrat that had just been annoying Howard.
- In Top 10, they mention that bulls are colorblind.
- Wonder Woman Vol 1: Mint Candy's love interest is a matador/matadora and when she turns her back on a bull that's still in its pen to answer a question the bull is enraged at her swinging red cape and manages to burst through the fence to try to attack her.
- Space Jam had Daffy painting the rear end of one of the Monstars red. This elicited great laughter from the Toons in the audience, until Toro, the bull from "Bully for Bugs" notices it, which is what Daffy was going for all along. Cue one Monstar going airborne involuntarily. "Bully For Bugs" itself has Bugs flapping his red matador cape in the bull's face, but Toro acts more fascinated than angry.
- Danny DeVito's character in Johnny Dangerously is whacked by handing him a Schlitz malt liquor and a red smoking jacket. Sure enough, the Schlitz Bull comes charging through the wall at him. Which, for those not aware, is a Shout-Out to Schlitz's famous late 70's/early 80's ad campaign where a bull would do a Kool-Aid Man wall crash at the end of each commercial.
- A rarer live-action example comes from Pee-wee's Big Adventure, when Simone's jealous ex Andy chases our hero into a Texas rodeo. A bull then catches sight of Andy's red shirt and chases him right out of the movie.
- Randle McMurphy in One Flew Over the Cuckoo's Nest references a similar phenomenon regarding chickens (one with more Truth in Television than the stereotype about bulls) to point out how Nurse Ratched's group therapy sessions pit the patients against each other and do more harm than good for their psychological well-being.
"Is this the usual pro-cedure for these Group Ther'py shindigs? Bunch of chickens at a peckin' party?...The flock gets sight of a spot of blood on some chicken and they all go to peckin' at it, see, till they rip the chicken to shreds, blood and bones and feathers. But usually a couple of the flock gets spotted in the fracas, then it's their turn. And a few more gets spots and gets pecked to death, and more and more. Oh, a peckin' party can wipe out the whole flock in a matter of a few hours, buddy, I seen it. A mighty awesome sight. The only way to prevent it — with chickens — is to clip blinders on them. So's they can't see...And thats just exactly what that meeting I just set through reminded me of, buddy, if you want to know the dirty truth. It reminded me of a flock of dirty chickens."
- In the Adam West Batman (1966), the trope is subverted when Batman escapes a deathtrap of being tied to the ground to be trampled by a herd of bulls. He frees himself and waves his cape to make the charging herd avoid him. When Robin notes he was able to do that without the cape being red, Batman tells him that cows are colorblind so the color of his cape didn't matter.
- Bullseye UK: During the last intro of Jim Bowen's run, he gets out a red cloth to mop himself, causing him to turn into a bullfighter in Bully's eyes.
- Empty Nest: After Harry is visited by his carefree globetrotting brother, he decides to travel to Pamplona for the Running of the Bulls, wearing a red sweater and no sunscreen. The episode ends with him frantically trying to remove the sweater as the bull herd approaches.
- Busted in one episode of MythBusters. The experiment culminated with a terrified Tory in a red jump suit standing very still in a rodeo ring with a temperamental bull. While rodeo clowns ran around distracting the bull, Tory was completely ignored. It did look for a time like he should have brought some brown pants.
- Further tested when three capes of different colors—red, yellow, and blue—were waved in front of a bull herd. Turns out that the bulls went after the yellow and blue capes as often as they charged the red one.
- A Monster of the Week in Ninja Sentai Kakuranger (not adapted to Mighty Morphin' Power Rangers) was a bull with a cowboy motif. At one point Ninjaman pulls out a red cape and begins waving it in front of him, causing the bull to become angry (even growing his horns) and drag him into a bullfighting game. When it grows to giant size, Ninjaman tries to pull the same trick, but the bull pulls out a rifle and shoots the cape instead.
- Marty Robbins: In "Utah Carol", a herd of stampeding cattle is further agitated by seeing a red blanket trailing behind on of the riders, prompting them into charging down towards her. Utah then uses the blanket to lure the herd away from the other riders at the cost of his own life.
- Warhammer Fantasy Battle: A single glimpse of the color red is sometimes sufficient to send minotaurs into a maddened frenzy, because it reminds them of the blood and bloody flesh that they obsessively hunger for.
- Ace Attorney Investigations: Miles Edgeworth: Discussed in the second game when examining a particular object in the first case. Kay wonders if a bull would be drawn to Edgeworth because of his clothes, and he points out (correctly) that it's not the color that draws the bull's attention, it's the movement. She then retorts that, in that case, the bull would still be compelled to charge at Edgeworth because of his cravat.
- Botanica: You need to hang a piece of red cloth in front of a bull-like animal to make it charge. The cloth is white initially, so you also have to gather items to dye it red first.
- Conker's Bad Fur Day has a boss battle against a bull that hates the colour red, and since Conker is a red squirrel...
- King's Quest VI: Heir Today, Gone Tomorrow: The hero manages to lure a minotaur into a trap by using a bright red scarf. The minotaur's growled comment: "Rrrrrreeed..."
- Neighbours From Hell 2: One of the pranks Woody does to Rotweiller is to paint the bench he is sleeping on red (Rotweiller wears a swimsuit in this game) and after he wakes up, the bull behind him becomes angry.
- Some Pokémon games' Pokédex entries on Tauros state outright that the color red is their Berserk Button.
- In Rulers of Nations, one of the consequences of being a bad leader is that you are killed by having an activist throw red paint on you while you are near a bull and then this causes said bull to gore you to death.
- Played with in one of Dribble's games in WarioWare, Inc.: Mega Microgame$!, which features a matador taunting a... rhino. Hey, male rhinos are called "bulls", too.
- The Beatles: In the episode "Please Please Me", the Fab Four are having a picnic in Spain, and Ringo is shaking ants off their red picnic blanket. It attracts a bull, causing John, Paul and George to run.
George: Ringo, look out!
Ringo: Why? These little nippers can't hurt you! (after the bull passes and tears the blanket with its horns) Hmm. They wasn't ants after all. They was moths!
- In The Berenstain Bears cartoon this trope was averted when the characters are told to distract the bull by waving their brown scout hats. As the smart one points out, it's not the color so much as the motion of the objects that makes them upset.
- In the Cars animated short "El Materdor", Mater tells Lightning the story about how he was a famous bulldozer fighter in Spain (bulldozers being the analog of bulls in this world). The bulldozers naturally react to Mater's red cape, and later to Lightning himself:
Mater: They sure liked that fancy red paintjob of yours.
- Classic Disney Shorts
- "For Whom the Bulls Toil" features a bull which only moves when Goofy produces a red handkerchief, with results that land Goofy in a Mexican bullfighting ring.
- In the Disney short "Mickey's Rival", Mickey Mouse's animate car lures a bull away by waving its red turnlight.
- Mickey Mouse (2013): Used in "Al Rojo Vivo". Pete once again tries to have Minnie to himself while Mickey is shoved into the running of the bulls and has to avoid the bulls, which is hard for him because fate seems obsessed with making him end up in areas with red objects.
- My Little Pony 'n Friends: In "The End of Flutter Valley, Part 7", Megan distracts a bull from Sting and Morning Glory by waving a red blanket at it and swiftly drawing its attention, complete with images of the red object appearing in its pupils.
- Phineas and Ferb: In "Robot Rodeo", robotic bulls go absolutely insane at the sight of a red balloon. Oddly, it works quite well. Fridge Brilliance applies here: The bulls are, as stated above, robots. They were probably programmed to react that way to the color red because that's how a couple of kids assume bulls should behave.
- Popeye: "For Better Or Nurse" has Bluto deliberately trying to injure himself (as is Popeye) so he can be near nurse Olive at a hospital. He tucks a red towel under his chin and taunts a nearby bull. Unfortunately for Bluto, the bull is smitten with the cow mascot of a dairy product ad billboard. When that script was recycled for the cartoon series that renamed Bluto as "Brutus", Popeye paints himself red to taunt a bull. Brutus pours invisible ink on Popeye to make the bull miss him.
- Scooby-Doo and the Cyber Chase: Spoofed when Fred uses Daphne's violet jacket to outmaneuver a charging lion, noting "it's not red, but it'll have to do". (In Fred's typical smartass fashion, he shouts "Leo!" because "Toro!" just provoked a "Where? Where?" reaction).
- In The Simpsons episode "Pokey Mom", the family is at a prison rodeo when one of the contestants is in danger. Homer lifts up Lisa and uses her red dress to get the bull to charge towards him, but runs into a snafu when he needs "a little calming blue":
Homer: (to Bart) Hey! Where's your blue shirt?
Bart: I don't have a blue shirt.
- Superman: The Animated Series. Superman is in a Tailor-Made Prison, trapped under a red light that neutralises his powers. He uses a shard of broken glass to reflect the red light into the eye of a large alien creature nearby, causing it to charge at his cell and break him open.
- An episode of Tiny Toon Adventures spoofing Star Wars features a bull named "Chewcudda". Never show Chewcudda anything red...not even your tongue.
- Woody Woodpecker encounters this moment in the early short The Hollywood Matador. It happens when the bull in question sees his red underside. (note: Woody's belly feathers were originally red)