History RedOniBlueOni / Sports

** Kobe Bryant (Red) of the Los Angeles Lakers and Tim Duncan (Blue) of the San Antonio Spurs were both hard-working, "greatest-of-all-time"-caliber superstars whose careers basically ran parallel to each other's[[note]]Not only were their rookie debuts only one year apart, but they both stayed with the same team their entire career, played a leading role in winning five championships each, and even retired in the exact same season[[/note]], but the players themselves could not be more different in terms of public persona. Kobe was outspoken, fashionable, and had a breathtakingly athletic playstyle that won him a massive worldwide fanbase (plus major endorsement and business deals) as "The Black Mamba", but also gained somewhat of a reputation for being a selfish player who enjoyed playing the heel. On his end, Duncan's efficient and unflashy playstyle won him accolades as "The Big Fundamental", a super-consistent and team-first player who didn't need flashy moves to beat the best, but his low-key personality (including a tendency to eschew most endorsements) and rather unfashionable dress sense led to multiple jokes about him being the NBA's most boring superstar (and a [[https://www.theonion.com/tag/tim-duncan long-running series]] in ''Website/TheOnion'' affectionately ribbing him for being ''too'' nice and sensible for the NBA).
** Karl Malone was the blue (blue-collar work-ethic, more reserved demeanor) to Charles Barkley's red oni (party animal, loud, very outspoken). Among the Utah Jazz, though, Malone was red (earthy Southerner) and John Stockton (serious Pacific Northwesterner) was blue.

** School colors also hold true for University of Nevada, Reno (blue and silver) and University of Nevada, Las Vegas (scarlet and gray). UNR is older, more academically respected and started branding their sports as "Nevada" after UNLV became prominent, hoping to distance themselves from their rival and emphasize that they're older. UNLV is larger and has had frequent run-ins with the NCAA, especially in its most prominent sport of men's basketball. And it extends to the cities as well: [[UsefulNotes/LasVegas Vegas]] as a flashy party town, Reno as more sedate and humble.
** This trope can be seen even in lower NCAA divisions. One especially notable example is Henderson State (red, and nicknamed Reddies, no less) and Ouachita[[note]]pronounced WASH-i-taw[[/note]] Baptist (purple, but fits the blue role like a glove), two Division II schools in Arkadelphia, Arkansas (permanent population a touch over 10,000), located literally across the street from each other. Their football rivalry, known as the [[https://en.wikipedia.org/wiki/Battle_of_the_Ravine Battle of the Ravine]] (from the ravine that runs through both campuses), [[https://www.si.com/college/2019/11/29/ouachita-baptist-henderson-state-rivalry was called]] "college football's most intimate rivalry" by ''Magazine/SportsIllustrated'' in 2019.[[labelnote:*]]How intimate? Just for one example, one of the game's most unique traditions is that on game day, the visiting team ''walks from its campus to the other team's stadium''. In full uniform (apart from helmets).[[/labelnote]] The ''SI'' piece also noted the contrasts between the two schools--Henderson State is public and "stereotypically fratty" (with OBU fans sometimes calling it "Heathen State") and Ouachita Baptist is private and "stereotypically snooty".

** Celtic and Rangers, also known as the Old Firm. Despite playing in green, Celtic are the red oni and represent the Irish Catholics of Glasgow whilst Rangers are the blue oni, play in royal blue and represent the British protestant establishment. Both represent the sectarian divisions of Glasgow and Northern Ireland. Also, Celtic fans were traditionally Labour voters whilst Rangers fans were traditionally Conservative voters.

** Luis Suárez, the fiery Uruguayan with a penchant for spectacular goals and a knack for being controversial, is the red oni to the blue oni of Sergio Agüero, the methodical Argentine who's a cold-blooded, clutch finisher with sound fundamentals. [[ColorCodedForYourConvenience This becomes even better when you look at the jerseys of their clubs.]] (Luis Suárez - Liverpool, next Barcelona, then Atlético Madrid; Sergio Agüero - Manchester City, though he ended his career with a brief stint at Barça.)

* Another [[UsefulNotes/NationalFootballLeague NFL]] rivalry, the San Francisco 49ers and Seattle Seahawks, carries this as a color scheme - and while the teams are [[ImplacableMan essentially very similar]], their coaches during the first part of the 2010s represent the trope perfectly. Pete Carroll of the 'Hawks has a jovial, [[CoolOldGuy bohemian]] vibe, is guarded but amiable [[NiceTotheWaiter with the media]], and plays it cool [[TranquilFury on the sidelines]], while the Niners' Jim Harbaugh (now back in college coaching at his alma mater of Michigan) is a self-admitted [[HotBlooded "jackhammer"]] known for his on-field [[LargeHam histrionics]], contentious-but-quotable [[TheSnarkKnight press conferences]], and habit of [[AFatherToHisMen taking snaps with his team in practice.]] It helps that they [[ItsPersonal legitimately despise each other.]]

** Alex Zanardi ('96-'98) and Juan Pablo Montoya ('99-'00) and Jimmy Vasser made an excellent case of Red Oni/Blue Oni teammates en route to winning four CART titles in five years.

* In German football, the passionate, attacking Borussia Dortmund (red, although they wear yellow) to the relatively calmer Schalke 04 (blue.)

* In golf, Arnold Palmer and later Lee Trevino (both red) to UsefulNotes/JackNicklaus (blue).

** UsefulNotes/ConorMcGregor (red) vs. Nate Diaz (blue), though in most other rivalries it is the Diaz brother who is the red, e.g. Nick Diaz (red) vs. Georges St. Pierre (blue)

** Michael Bisping (red) vs. Georges St. Pierre (blue)

** Dominick Cruz (red) vs. Team Alpha Male (blue). Fittingly, whenever a Team Alpha Male fighter would fight Cruz, they would fight in blue shorts. Though this began to reverse during the actual fight of Garbrandt-Cruz.

** Lewis Hamilton (red) to Jenson Button (blue)