Palette-swap

A palette swap is a practice used in video games, whereby a graphic that is already used for one element is given a different palette, so it can be reused as other elements. The different palette gives the new graphic another set of colors, which makes it recognizably distinct from the original. Palette swaps are commonly used to distinguish between first and second players, for creating visual hierarchies, and for making visually distinct areas for levels in games.

One reason palette swaps are used is to save memory. In early computer gaming, when cartridges were the main storage medium and memory capacity was both scarce and expensive, a single sprite could be reused by changing its palette. As such, many new objects could be created without the need to produce new graphics from scratch, which saved both production costs and development time. Early games in the Mortal Kombat series frequently introduced new ninja characters via palette swapping as both a cost-cutting and memory-preservation measure. More generally, palette swaps are common in sports games, in which the color scheme of opposing players is used to differentiate between teams.

In certain cases, such as role-playing video games, palette swaps are used to signify a character's status. Prominent examples of this are seen in Final Fantasy, in which a player character afflicted with the "Poison" Status effect will appear purple. In other games, such as Dragon Quest IX or Dark Cloud 2, palette swaps are used for mobs to distinguish higher level enemies. By contrast, the main characters of Breath of Fire II occasionally swap their palette colors to indicate an increase in their respective statistics. In Mario Bros., Super Mario Bros., Super Mario Bros. 3, Super Mario World (except in the Super Mario All-Stars versions of the latter three, as well the Super Mario Advance series), and Mario is Missing! (NES and SNES versions), Luigi is a palette swap of Mario. In NES games such as Metroid, The Legend of Zelda, and Castlevania, palette swaps are used to distinguish stronger enemies. In Mortal Kombat, Scorpion, Sub-Zero, and secret character Reptile were palette swaps of each other, using yellow, blue and green, respectively. In Mortal Kombat II, Kitana, Mileena, and secret character Jade were palette swaps of each other, using blue, purple and green, respectively. Mortal Kombat 3, Ultimate Mortal Kombat 3, and Mortal Kombat Trilogy introduced multiple palette swaps including Cyrax, Sektor, and Ermac.

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