History RedOniBlueOni / WesternAnimation

** Leonardo (blue) and Raphael (red). Reversal in that Leo is the leader of the team (aside from [[OldMaster Splinter]]). Raph does the BloodKnight bit when he takes the guise of [[spoiler: Nightwatcher]] in the CGI movie. It was noted with this exchange from the first episode of the [[WesternAnimation/TeenageMutantNinjaTurtles2003 '03 series]]:

* ''Franchise/Transformers''

*** Starscream, the gung-ho backstabber, with Thundercracker, the more reluctant henchman.

*** Marvel Comics continuity in particular played up the contrast between Blue Oni Autobot leader Optimus Prime (calm, noble and rational) and Red Oni Dinobot (and sometimes all Autobots) leader Grimlock (impulsive, violent and bombastic).

* The wild, combative and sarcastic Rayla from ''WesternAnimation/TheDragonPrince'' is a red oni. Callum, on the other hand, is calmer and more reserved, and therefore a blue oni.

* ''RedOniBlueOni/TheLoudHouse''
* ''RedOniBlueOni/MyLittlePonyFriendshipIsMagic''
* ''RedOniBlueOni/{{Transformers}}''

* ''Franchise/ThePowerpuffGirls'': Zigzagged. has aggressive Buttercup and emotional Bubbles respectively, with Blossom in-between (being the blue oni to Buttercup's red and the red oni to Bubbles's blue). On occasions, Bubbles can be the gleeful red to Blossom and Buttercup’s blue.

** Fry (red) and Leela (blue). Fry is a [[IdiotHero simpleminded]], impulsive, hyperactive ManChild who often ignores the responsibilities of his job thanks to a short attention span and sheer [[TheSlacker laziness]], while Leela is a mature, intelligent, somewhat stoic space captain whose dedicated to the job, prioritizing the rules and punishing Fry and Bender whenever they don't follow orders. Blurring the lines a little is that Leela and Fry are a MasculineGirlFeminineBoy pair, with Leela being a highly efficient ActionGirl with BloodKnight tendencies and Fry being a CowardlyLion whose more likely to hide behind her and scream in dangerous situations. Though he does step up when the situation calls for it.

** [[ZigZaggingTrope Zig-Zagged]] with Finn and Jake. In earlier episodes, Finn was the HotBlooded and headstrong Red Oni who relies on force and charges in headfirst and Jake is the wise and reasoning Blue Oni. Later episodes depicted Jake as the mischievous and bone-headed Red and Finn as a good natured and friendly Blue.

** Gumball's mother, Nicole is very ill-tempered, mature and strict, while Richard, Gumball's father, is laid-back and calm. Again, this ironic, since Nicole's fur is blue while Richard's is pink.

** In ''Life with Loopy'', Loopy is the red oni (energetic, life-loving) to her older brother Larry's blue oni (inteligent, shy). Oddly enough, the colors of their hair are the opposite (Loopy has blue hair, Larry has red).
* ''WesternAnimation/KidCosmic'': this has two cases of this

* In ''WesternAnimation/LooneyTunes'', WesternAnimation/DaffyDuck serves as the hot-tempered, overacting, obnoxious red oni to WesternAnimation/BugsBunny, who is a calm, cool, intelligent blue oni. Bugs himself becomes the red oni when contrasted to Cecil Turtle the the ''Tortoise and Hare'' based cartoons.

** D.W. (Red) is generally bratty, self-centered and prone to throwing temper tantrums when not getting her way. Arthur (Blue), meanwhile, is generally reasonable and mature.

** Muffy (Red) is a [[LovableAlphaBitch lovable]] RichBitch, while Francine (Blue) is friendly and out-going.

* WesternAnimation/{{Amphibia}}: This pretty much sums up the relationship between General Yunan and Lady Olivia, particularly showcased in their starring self titled episode. It helps that, like the Steven Universe example below, they literally are red and blue.
* ''WesternAnimation/AmericanDragonJakeLong'': As per their clothing and dragon forms, Jake is the Red Oni to his grandfather's Blue.

* ''WesternAnimation/BeavisAndButthead''. While both of the boys are active pranksters and neither of them show good judgement, Beavis is HotBlooded, brash, irritable, and violent, while Butthead is more laid-back, calmer, and (barely) smarter. Ironically, Beavis wears a blue shirt while Butthead wears red shorts.

* ''WesternAnimation/BobsBurgers'', [[FantasyForbiddingFather Bob]] (blue) is the somber, mostly calm and hardworking Dad. While [[GenkiGirl Linda]] (red) is the optimistic, quirky and sensitive Mom.

* ''WesternAnimation/GravityFalls'' has the studious and thoughtful SeekerArchetype Dipper (Blue Oni) and the loud and boisterous GenkiGirl Mabel (Red Oni).

* In ''WesternAnimation/InvaderZim'':

* In ''WesternAnimation/OverTheGardenWall'' older brother Wirt is an angsty, intellectual, chronic overthinker while his younger brother Greg is a loud, excitable doer.

* ''WesternAnimation/TheOwlHouse'': Luz is the excitable, impulsive Red Oni to Amity's reserved, studious Blue. Interestingly their color schemes invert this, with Luz's default outfit being lavender and blue while Amity wears orchid or reddish magenta. This even extends to their first elemental spells, with Luz learning how to create ice columns in the same episode where Amity learns to conjure fireballs.

* ''Franchise/ThePowerpuffGirls'' Zigzagged. has aggressive Buttercup and emotional Bubbles respectively, with Blossom in-between (being the blue oni to Buttercup's red and the red oni to Bubbles's blue). On occasions, Bubbles can be the gleeful red to Blossom and Buttercup’s blue.

* ''WesternAnimation/StarWarsTheCloneWars'': Ahsoka Tano is the Red to Barriss Offee's Blue. They even have color-coordinated starfighters. Even when [[spoiler: Barriss [[FaceHeelTurn fell to the dark side of the Force]]]], she displayed all the traits of a villainous [[spoiler: Blue]] Oni.
** On the Separatist side, [[CulturedWarrior Count Dooku]] was definitely the stern, refined Blue to [[GeneralRipper General Grievous's]] short-tempered Red.
** Jedi Apprentice Ahsoka is also the Red to [[spoiler: Former]] Assassin Asajj Ventress's Blue. Ahsoka generally being the naive learner, taking on many of [[StudentAndMasterTeam Anakin's traits]]. While Ventress took on more of [[ManipulativeBastard Dooku's traits]], despite not officially being a Sith.
** A curious example can be found between [[SiblingYinYang Savage and Maul]]. Though both have been shown to be aggressive, Savage Oppress (Red) is more like [[TheBrute The Brute]] with a short temper and even shorter patience. Maul (Blue) on the other hand shows more restraint in his anger (even during his crazed state), he was also a shrewd survivor who served as the mouth to Savage's muscle.

* ''Series/SquareOneTV'' inverts this trope with their animated sketch series ''Zook & Alison'', The boy, Zook, is loud, nervous, and outgoing, but is Blue in color, while his Pink sister, Alison, is calmer and smarter.

* ''WesternAnimation/StarWarsRebels'': Garazeb "Zeb" Orrelios is the Red to Agent Kallus' Blue. Zeb's the [[BloodKnight gung-ho]], ProudWarriorRaceGuy with a [[HotBlooded hot temper]] is on the side of the Rebels to Agent Kallus' calmer and more orderly, [[MagnificentBastard manipulative]] nature for the Empire. Both of them found mutual respect for one another based on their adherence to their honour code and [[DeadpanSnarker Deadpan Snarker]] tendencies [[spoiler: and the fact that Zeb saved Kallus' life when they were stranded on one of Geonosis's moons.]]

* Sparx the red monkey and Gibson the blue monkey from ''WesternAnimation/SuperRobotMonkeyTeamHyperForceGo!''.

* Corneil (blue) and Bernie (red) from ''WesternAnimation/WatchMyChops''.

* In ''WesternAnimation/YoungJustice2010'' the main team has Superboy, Kid Flash and Miss Martian as the Red to Aqualad, Robin and Artemis's Blue respectively. Red Arrow also plays Red to Aqualad's Blue when they're together.

* In ''WesternAnimation/RegularShow'', Mordecai (blue) and Margaret (red) deliberately follow this trope -- both in appearance and personality. To a greater extent, there's the relationships between Mordecai and Rigby, and the relationship between Muscle Man and High Five Ghost.
* ''WesternAnimation/RenAndStimpy'': Ren (Red Oni) is often hot-headed, borderline psychopathic and unstable, while Stimpy (Blue Oni), as much as an "eediot" he is, is easily much more reserved and rational than Ren. Funnily enough, Stimpy is the ''blue'' oni despite being a ''red'' cat.

** Jacques and Josee. Josee is in the red due to being very hot headed as she throws tantrums when she and Jacques place anywhere other than first and Jacques is in the blue as he constantly fears Josee's tantrums and constantly ScreamsLikeALittleGirl.

** The Bigheads are a good example. Ed Bighead is loud, short-tempered and spiteful (red) while Bev has a moral compass and doesn't have any resentment towards Rocko, Heffer or Filburt (blue)

* Both played straight and inverted on ''WesternAnimation/{{Rupert}}'': The protagonist Rupert Bear wears red and is an adventure-loving thrill seeker who's always eager to swing into action and come up with an IndyPloy to save the day; his [[TheLancer Lancer]] Bill Badger wears blue, is far more cynical and snarky, and is reluctantly dragged along on all the hero's adventures. In a twist, Rupert is definitely the more level-headed one, while Bill is more reckless and prone to acting without thinking. However you look at it, the two are opposites... [[OddFriendship and best friends]].

** In the 2017 continuation, Ashi acts is the determined Red oni to Jack's sullen Blue.

** Catra and Adora. Adora is heroic, mature, and reasonable, while Catra is wild, cocky, manipulative and very brash who only hurts people so she can get what she wants.
** Glimmer's Red to Bow's Blue also count as this. With Glimmer being rebellious and reckless, while Bow being polite and symphatetic.
** Catra's Red Oni to Scorpia's Blue Oni. Catra is uptight, short-tempered, and cruel, while Scorpia is friendly, kind and polite. Since Entrapta is sweet and a bit hyperactive who does some dangerous things, she can be the Blue Oni to Scorpia's Red Oni or the Red Oni to Catra's Blue Oni.

** There's also Bart's red (hyperactive, mischievous and has a disdain for authority figures) to Lisa's blue (smart, good-natured and generally obedient).
** Groundskeeper Willie has a HairTriggerTemper and shows resentment towards Skinner (red), while Principal Skinner is consistently shown as an ExtremeDoormat towards Chalmers and his mother, and barely manages to keep the school open (blue).

* ''WesternAnimation/{{Spliced}}'': Peri is the nice and kindhearted Blue Oni to Entree's stubborn, impulsive and insensitive Red Oni.
* ''WesternAnimation/StarWarsRebels'': Garazeb "Zeb" Orrelios is the Red to Agent Kallus' Blue. Zeb's the [[BloodKnight gung-ho]], ProudWarriorRaceGuy with a [[HotBlooded hot temper]] is on the side of the Rebels to Agent Kallus' calmer and more orderly, [[MagnificentBastard manipulative]] nature for the Empire. Both of them found mutual respect for one another based off their adherence to their honour code and [[DeadpanSnarker Deadpan Snarker]] tendencies [[spoiler: and the fact that Zeb saved Kallus' life when they were stranded on one of Geonosis' moons.]]

** [[TomboyAndGirlyGirl Ruby and Sapphire]], the two Gems who [[spoiler:fuse into Garnet]]. When forcibly separated and put into different prisons, Ruby is angry and nerve-wracked, going around screaming Sapphire's name as soon as she's freed; Sapphire, in contrast, calmly sings her in cell, and uses her freedom to [[SuperSpeed quickly]] and efficiently hunt Ruby down so that they can [[spoiler:fuse again]]. This extends to PersonalityPowers in "Keystone Motel", as the pair respectively become very hot and very cold -- [[PlayingWithFire quite]] [[AnIcePerson literally]] -- when they're angry at each other. Keystone Motel also lets us get to know them better -- Ruby's emotions are very much worn on her sleeve while Sapphire is outright TheSpock. [[spoiler:Believe it or not, their roles are reversed in "Now We're Only Falling Apart", as Sapphire (red) is absolutely ''[[BrokenPedestal livid]]'' at the revelation that Rose [[TwoAliasesOneCharacter is]] Pink Diamond, whereas Ruby (blue) takes the revelation [[EasilyForgiven quite well]].]]
** The titular [[{{Keet}} Steven]] is goofy, outgoing, and wears a red shirt, while his best friend Connie is more quiet, intellectual, and wears blue in the first intro and several episodes (for example, "Alone Together".)
** Yellow Diamond, who has a [[HairTriggerTemper volcanic temper]], is the red to her 'sister' Blue Diamond's blue, as she is mostly melancholic these days. [[spoiler:Their other 'sister', Pink Diamond, is the red to both Blue and Yellow's blue.]]

* ''Franchise/ThePowerpuffGirls'' has Buttercup and Blossom respectively, with Bubbles in-between (being the blue oni to Buttercup's red and the red oni to Blossom's blue).

* ''WesternAnimation/{{Wakfu}}'' has this dynamic between [[TheChick Amalia]] and [[TheLancer Evangeline]]. Amalia is a RebelliousPrincess who absconds for little reason other than boredom and brattiness. Meanwhile, Evangeline starts as a [[TheStoic stoic]] TykeBomb with UndyingLoyalty to the Sadida royal family. She is all about duty and self-denial and doing what's right. But as things go on, they both learn from each other and end up reaching more balanced positions on the matter of responsibility. Amalia learns from the example of Evangeline's courage and commitment, taking up the challenge of living up to her royal responsibilities and defending the Sadida kingdom at its darkest hour. Evangeline, at the same time, learns how to enjoy herself without compromising her duty.

* ''WesternAnimation/PetAlien'': Tommy Cadle is the calm, reasonable blue oni, while his alien best friend Dinko is the manic, hyperactive red oni.

* WesternAnimation/{{Amphibia}}:
This pretty much sums up the relationship between General Yunan and Lady Olivia, particularly showcased in their starring self titled episode. It helps that, like the Steven Universe example below, they literally are red and blue.

** Loud, fun-loving, impulsive, bone-headed, [[ThePollyanna optimistic]] Owen (red oni) has an OddFriendship with the quiet, anti-social, calculating, intelligent, [[GrumpyBear gloomy]] (blue oni) Noah. Ironically, Owen wears a white t-shirt with a large blue maple leaf on it while Noah wears a red sweater vest.

** Gumball is enthusiastic, impulsive, and troublesome, while his brother Darwin is naïve, cautious, and calm, although Gumball's fur is blue and Darwin's scale is orange (a close tone to red). However, in later episodes such as [[Recap/TheAmazingWorldOfGumballS3E22TheBros The Bros]] and [[Recap/TheAmazingWorldOfGumballS6E43TheBFFS The BFFs]], Darwin is a impulsive, short-tempered, cheerful, and immature Red Oni, while Gumball is a tolerable, compliant-ish, sensitive, and a gentle [[DeadpanSnarker snarker]] [[JerkWithAHeartOfGold with a heart of gold]] Blue Oni.

* ''WesternAnimation/FostersHomeForImaginaryFriends'': Bloo (red oni) is obnoxious, self-centered, and rude, while Mac (blue oni) is intelligent, shy, and always wants to do the right thing (most of the time). Ironically, Mac normally wears a red T-shirt, while Bloo is, well, [[ExactlyWhatItSaysOnTheTin blue]].

** Adora is heroic and the reasonable Blue Oni, while Catra is manipulative and the emotional Red Oni.

** Catra's Red Oni to Scorpia's Blue Oni. Catra is bossy, mean, short-tempered, and cruel, while Scorpia is friendly, kind and polite. Since Entrapta is sweet and a bit hyperactive who does some dangerous things, she can be placed on either red or blue.

* ''WesternAnimation/{{Breadwinners}}'': SwaySway is the Blue Oni to Buhdeuce's Red; the former is the relatively coolheaded leader while the latter is the more hotheaded, impulsive follower. It's even reflected in the colors of their uniforms.

* ''WesternAnimation/Breadwinners'': SwaySway is the Blue Oni to Buhdeuce's Red; the former is the relatively coolheaded leader while the latter is the more hotheaded, impulsive follower. It's even reflected in the colors of their uniforms.

* ''WesternAnimation/PhineasAndFerb'', respectively. Phineas is the talkative extrovert, while Ferb is TheQuietOne. Phineas also has red hair, while Ferb's is green.

** Gumball is impulsive, passionate and reckless, while his brother Darwin is naïve, cautious and calm, although Gumball's fur is blue and Darwin's scale is orange (a close tone to red).

** Jet's cousin Zerk is the Red Oni to Jet's Blue Oni. Zerk takes Jet's {{Keet}} tendencies UpToEleven and then some, while Jet is more responsible than him and tries to be patient with his antics.