User can create, shape and manipulate colors, attribute of things that results from the light they reflect, transmit, or emit in so far as this light causes a visual sensation that depends on its wavelengths.
Note that while this ability alone doesn't grant any other abilities, colors have certain symbolic connections and if those connections exist in the given world, this ability allows controlling them.
Zero (Mega Man Zero); via Form Change (Zero 2), or Armor Change (Zero 3 and 4)
Megaman.exe (Mega Man Battle Network); via Style Change (Battle Network 2 and 3 only)
Aqua (Kingdom Hearts); via Prism Rain
Sora (Kingdom Hearts); via Drive Forms
Five core ToQgers (Ressha Sentai ToQger) via Transfer Change
DJ Octavio (Splatoon)
Black Lily (Valkyrie Crusade)
Prismatic Master (Valkyrie Crusade)
Discord (My Little Pony: Friendship is Magic)
Spooky Spoon (Numberjacks)
Bella Lovely (The Girl Who Could Fly)
Rainbow Star (Xiaolin Showdown)
Lady Rainicorn (Adventure Time) can alter the color of objects.
Sweet (Buffy the Vampire Slayer) can alter the color of his suit at will.
Color Kid (DC Comics) possessed the ability to change the color of anything
Sora (Kingdom Hearts II) can change the color of his clothes when he uses his Drive Forms such as in Kingdom Hearts II Final Mix when he uses Limit Form it changes his clothes to the same coloring as his clothes from the original Kingdom Hearts game.
Right/ToQ 1gou and Tokkati/ToQ 2gou (Ressha Sentai ToQger) can change colors to each other with the use Transfer Change by exchanging their miniature Ressha and inserting them into their transformation devices. Their signature weapons change upon transfer.
Inklings (Splatoon) can change the colors of their tentacle "hair" and ink to match the team they are on in multiplayer mode.
Agent 3 (Splatoon) can change the color of their tentacle "hair" and ink depending on the mission they are undertaking in Octo Valley mode...
...and can change the color of the ink that the Octobot King's octomissiles generate from dark fuchsia to orange or yellow by damaging them enough. However...
...DJ Octavio can use the Octobot King's rocket fists to change the octomissiles' ink color back to dark fuchsia.
Callie (Splatoon, left) can change the tinge on the ends of her tentacle "bangs" to match the team she is rooting for during Splatfest.
Octolings (Splatoon) can change the color of their tentacle "hair" from red to black to signify that they have reached elite status and are far tougher than other Octolings.
Black Lily (Valkyrie Crusade) essentially controls black, both literally (as a color) and metaphorically.
Prismatic Master (Valkyrie Crusade) can control the seven colors of the rainbow.
Discord (My Little Pony: Friendship is Magic) turning a white tablecloth red by a simple touch