[[quoteright:330:[[Film/{{Tron}} http://static.tvtropes.org/pmwiki/pub/images/TronFlynnChangesColor_9882.jpg]]]]
[[caption-width-right:330:[-Well, at least no one can accuse Flynn of [[IncrediblyLamePun turning]] [[DirtyCoward yellow]]! [[note]](His [[EvilTwin evil]] [[NinjaPirateZombieRobot cyber]] [[EnemyWithin duplicate]], on [[Film/TronLegacy the other hand...)[[/note]] ]]-] ]]

Video games, movies, and other media action can be fast paced and potentially confusing. Telling apart TheCavalry from the EliteMooks they're engaging is complicated by the camera moving and lack of good lighting; this is why factions are DressCodedForYourConvenience and members of SuperTeam are ColorCodedCharacters. If there's energy attacks, so are they. {{Ray Gun}}s will have the color of the faction, and even normal guns' [[EveryBulletIsATracer tracer rounds]] will be the same color.

Which works fine until the hero or a villain picks up the opponent's costume, weapons, or vehicles. Going a step further, what about characters who switch sides like the henchmen pulling a MookFaceTurn? What ends up happening is a [[TitleDrop Convenient Color Change]]. The clothing, weapon, vehicle, character, building, or even ''city'' will change their default color to the one they're now aligned with. In the case of an infiltrator, the "how" for this color change is usually glossed over, but if a reason is given, it's that the colored areas are kind of like a high tech/magical mood ring.

There's a lot of variations on this. MechaMooks that get [[HackingMinigame hacked]] will spontaneously change the color of any lights on their chassis, as if they were built with multiple colored bulbs just in case they were ever hacked[[note]](or the owner wants to mod them)[[/note]]. Characters under MindControl or the effects of TheVirus may have this happen to them as well.

This tends to be a staple of strategy games if different players have the same units and structures at their disposal, because you ''do'' need a way to tell your forces apart from your opponents', hence the use of ColorCodedArmies and ColorCodedMultiplayer. In this and other settings, a unit/character that can change color ''without'' changing alliances serves as an infiltrator.

PaintItBlack is a subtrope of this. See also EyeColourChange.
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!!Examples

[[foldercontrol]]

[[folder:Anime & Manga]]
* In ''Anime/MagicalGirlLyricalNanohaStrikerS'', Subaru receives her sister's magical Device from her for the FinalBattle. At first, it remains purple (her sister's signature color), but when she is preparing a powerful spell, it turns blue (Subaru's color), just like her own twin Device.
[[/folder]]

[[folder:Films -- Live-Action]]
* In the Film/{{Tron}} universe, vehicles change to the color of whatever program is piloting it. Also, programs that are [[{{Brainwashing}} reprogrammed]] (or {{deprogram}}med) may change color. The page picture is Flynn [[InvokedTrope invoking the trope]] in order to pass himself off as a {{Mook}}. {{Justified|Trope}} in that a Program's circuitry indicates its alignment and job within the system.
** We see this not only in the movies, but in the video games ([[VideoGame/TronEvolution Abarax]] turns an awful greenish color), and the AlternateContinuity of ''VideoGame/TronTwoPointOh'' shows a hapless infected Program transforming from blue circuitry to SicklyGreenGlow as well as an EvilCostumeSwitch for [[spoiler: Ma3a]] when she compiles with some malicious code.
* In an early draft of ''StarWars'', lightsabers worked like this.
[[/folder]]

[[folder:Web Comics]]
* In ''ErfWorld'', raiment has similar properties. It changes color and even ''symbol'' depending on who a unit serves. So when Wanda [[TheUndead uncroacks]] or [[BackFromTheDead Decrypts]] a unit, its raiment immediately changes to her or Parson's symbol.
* Magic weapons in ''{{Goblins}}'' are explicitly said to glow with the [[AuraVision aura color]] of their wielder and change depending on who is wielding them.
[[/folder]]

[[folder:Video Games]]
* In ''{{Paperboy}}'', when a house cancels its subscription (because of your incompetence), its paint suddenly turns gray and metal skulls appear on its fenceposts.
* The security bots in ''Franchise/{{Bioshock}}'' change from red-light to green-light when you hack them. Likewise, Big Daddies' helmet lights will turn green when hypnotized and red when aggro'd.
* When buildings are captured in ''CommandAndConquer'' games (or when soldiers are mind-controlled), they change to the color of the team that captured them. GarrisonableStructures also get instant sandbags, flags, and color-coded paint jobs.
* In ''{{Dune II}}'', when an Ordos Deviator tank hit an opposing unit and put it under Ordos control, the unit's color changed to Ordos green.
* ''VideoGame/GearsOfWar'': The light on guns change to either blue or red depending upon which side picks them up.
* ''VideoGame/StarCraft'' has it for mind-controlled units in the ''Brood War'' extension, but averts it for "rescuable" units in missions (usually heroes).
** [[VideoGame/StarCraftII The sequel]] also does this, with the color of mind controlled units changing to the controller's side as long as they are being controlled.
** Campaign or custom map triggers that change unit control will also change the color accordingly. E.g. One early mission has you bring your hero unit to a beacon, which sets off a script to turn the whole base to your control, along with a new paint job.
* Though not universally true, ''VideoGame/FireEmblem'' characters will often switch their outfits to blue instead of green (NPC) or red (enemy) upon joining the player's army.
* In ''VideoGame/TheLegendOfZeldaSpiritTracks'', Phantoms being controlled by Zelda turn pink.
* ''VideoGame/ElShaddaiAscensionOfTheMetatron'' has the weapons change color from black to white as soon as you steal (and purify) them from enemies.
* In ''StarWarsBattlefront'', any command posts you/the enemy captures will change colour.
* At one point in ''TransformersWarForCybertron'', an Autobot [[EliteMook Brute]] picks up the hammer weapon dropped by the Decepticon Brute he just killed. The weapon immediately switches from the purple-tinted Decepticon version to the red-tinted Autobot version of the same weapon.
[[/folder]]

[[folder:Western Animation]]
* The [[FamilyFriendlyFirearms laser guns]] of ''GIJoe'' act like this. The beams are ColorCodedForYourConvenience, good guys and bad guys having different-colored laser blasts, and infamously, in one episode, a Cobra weapon is picked up and used by a Joe, and the color of its fire ''changed to match its user.'' It is joked by fans that the guns have a "good" and "evil" setting.
* In ''WesternAnimation/CodeLyoko'', Ulrich's katana usually glows blue when striking or parrying, but in the hand of a XANA-controlled warrior (like a polymorphic clone, a brainwashed Aelita, or [[TheDragon William]]), it glows red instead.
* In ''TransformersAnimated'', when Mixmaster and Scrapper [[FaceHeelTurn change their allegiance to the Decepticons]], their [[CallARabbitASmeerp optics]] go from yellow to red, as Autobots have blue eyes and Decepticons have red ones. They also go from the colors of the vehicles they were made from to the bright yellow and purple of the G1 Constructicons.
** The franchise also has many, many, maaaany characters over the years get a repaint from a powerup, sometimes temporary and sometimes permanent, because it lets them [[MerchandiseDriven sell the same toy again]].
* In ''Ben10AlienForce,'' Albedo is an alien who created a knockoff [[TransformationTrinket Omnitrix]] that has synced with Ben's, rendering him stuck with Ben's normal human form as his default. Eventually, the two Omnitrixes react to each other, and Albedo becomes a color-inverted Ben - dark hair becomes white, green clothes become red. Eventually, he creates another, better one called the Ultimatrix. It's red, like his jacket. So is the flash created when Albedo transforms with it. Then Ben gets it... and when he puts it on, it becomes green, as is the flash when ''he'' transforms with it.
[[/folder]]
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