Gravity, when depicted as an element, tends to be quite tough to visually represent in media, what with it being an invisible force and all. Well, wind has a similar problem with being colorless, but people from Asia decided to just depict it as green at some point. Maybe they also came with a solution for this? What kind of color would they use to represent gravity?
The answer appears to be purple most of the time. This color does appear to be very popular to associate gravity with in East Asian media. Now, the logic for this one doesn't appear to be very obvious at first. Is it because gravity is powerful? Or maybe otherworldy? After all, purple is viewed as a space-ish color, despite outer space being mostly black (but then again, Purple Is the New Black). In Western media, gravity tends to have more diverse coloring (assuming it even has color in the first place), with purple occasionally showing up as well.
Like gravity, darkness also tends to be associated with purple color schemes, and is not uncommon for both elements to overlap with each other. In this case, some black or dark blue may be mixed with the purple. Black Holes are a popular result of this elemental blending, and they're also often depicted with purplish tints despite their name (again, because Purple Is the New Black). Expect Gravity Masters to have purplish motifs too.
- Black Cat: The Brute Maro can both control the gravity around him and project super-dense gravity bombs, which are purple-colored.
- D.Gray-Man: Eshi, one of the Akuma, is able to create "Gravity Chains", which are purple and made of dark matter.
- Digimon Xros Wars: Gravimon's gravity techniques have purple energy effects on them.
- Fairy Tail: Bluenote Stinger, one of the antagonists of the Tenrou Island Arc, uses Gravity Magic, which mixes black with two or three different shades of purple.
- In Metal Fight Beyblade, Julian Konzern owns a beyblade named Black Excalibur which is a Gravity Master. The bey itself has a black-purple color scheme and its bey spirit is portrayed with a light purple color palette.
- One Piece: Issho, a.k.a. Admiral Fujitora, is able to manipulate gravity, which usually manifests as purple energy waves. He follows the tradition of Marine Admirals wearing attire whose color palette matches their Elemental Powers.
- Zatch Bell!: Brago, who fills the role of The Rival. His gravity is portrayed as both black or purple (or even both) depending on the spell he uses.
- Future Card Buddyfight: Most of Gaito Kurouzu's items and spells are gravity-related, and he himself wears a ton of purple, hair included.
- My Hero Academia: It's very subtle, but a flash of purple light sometimes appears around Uraraka's fingers when she activates her antigravity powers.
- BoBoiBoy: The character Yaya Yah's gravity manipulation is depicted as purplish pink, and she appropriately wears lots of pink and purple.
- Roxy "Freefall" Spalding from Gen¹³ has her gravity represented through purple energy or sparkles several times. She also has a preference for purple clothing.
- Starman: Thom Kallor/Star Boy sometimes has purple effects show up when he uses his gravity manipulation powers. His original costume was also primarily purple.
- In BIONICLE, purple is the primary color of Matoran, Toa, and Turaga of Gravity.
- The Gravity Bomb from Bomberman 64: The Second Attack! causes a dark purple "explosion" that sucks everything found within its radius into a black hole, located at its center.
- Dota 2: The hero Enigma is said to be the Anthropomorphic Personification of gravity itself. He is always surrounded by a light purple aura.
- The Final Fantasy has the spell Gravity/Gravira/Graviga (occasionally known as Demi), a Percent Damage Attack that is often colored purple with black, reflecting on how the gravity element is sometimes lumped with the darkness element.
- The Falchion β from Gradius Gaiden has the "Gravity Bullet" as a possible weapon which is basically a purple bullet that explodes into a purple Sphere of Destruction.
- The gravity lifts from Halo employ gratuitous purple gravity effects.
- The tractor beam tool in Insanely Twisted Shadow Planet is purple, as are objects that can be manipulated with it.
- Kingdom Hearts has Gravity spells in the first game and Chain of Memories. In the former game, they're purple mixed with black (as a nod to Final Fantasy's own Gravity spell), while in the latter, they're just purple.
- Magneto's attacks in the Marvel vs. Capcom series heavily employ his lesser known Gravity Master skills and are all colored purple.
- Mega Man 5: Gravity Man's... well, gravity, is shown colored purple and dark blue in at least one official artwork.
- Mega Man X:
- Mega Man X3: The Gravity Well weapon, used by Gravity Beetle (and X), has pale purple tones in official artwork. X also gets a primarily pinkish purple armor when equipped with it.
- Mega Man X8: Gravity Antonion's weapon, the Squeeze Bomb (which X can copy after defeating him), is colored black and purple.
- Metroid: The Gravity Suit, a recurring upgrade for Samus, is purple-colored in most games (The Prime games make it more bluish gray). However, a more literal example of this trope is in Other M, where the Gravity Suit is just a feature of the Varia Suit instead of its own thing. Activating it causes Samus to be surrounded by a purple aura, turning her immune to all gravitational effects. In addition, in Other M, passages with strong gravity have dark purple walls.
- Ninja Gaiden: The Art of The Piercing Void, one of Ryu's most powerful ninja techniques, allows him to control gravity in order to create a black hole surrounded by purple energy.
- In Overwatch, Zarya's ultimate, Graviton Surge, is a swirling vortex of energy with streaks of dark blues and purples.
- The Pokémon move Gravity, which grounds all Pokemon currently in the battlefield (leaving them open to Ground-type moves while also preventing airborne techniques from being used), was depicted as a downward, dark purplish wave in Generations IV and V.
- Ratchet & Clank: Into the Nexus: All of the gravity manipulation-themed puzzles are depicted with a very saturated purple including the grav streams that you generate with the Grav-Tether and use to get to new areas.
- The G-Lifter from Rochard is a sort of gravity gun that fires purple gravitational energy that moves objects around.
- The Violet Void power up from Sonic Colors turns Sonic into a violet-colored, living black hole.
- The Gravitron boss from Strider is a machine that emanates a violet gravity field around itself.
- In Super Robot Wars, every gravity- and graviton-based attack is black with purple highlights. This is also true concerning their black hole attacks, strange enough.
- Jackie Chan Adventures: Tso Lan, the Demon Sorcerer of Moon, is able to alter gravity through dark purple beams. His outfit is a red and purple Chinese robe.
- The Galaxy Trio: Gravity Girl is a costume example. Her outfit is almost entirely purple and violet, but her gravity rays are white (most of the time, at least).