Color changer

Color changers are effects or spells that change a spell or permanent to a particular color (mostly until end of turn). Note that the color-changing effects are not the same as the subtype of text-changing effects. Blue is the primary color of changing the color of other things. Green can change itself. And white and black can make things their own color. As R&D has lessened the number of effects that care about color, this ability isn't used much these days.

Change to White
Creature
 * Aurora Griffin
 * Cloudchaser Kestrel
 * Eight-and-a-Half-Tails

Enchantment
 * Celestial Dawn (cards you own)

Instant
 * Niveous Wisps (also taps it)
 * Purelace (permanent color change)
 * Heaven's Gate (any number of target creatures)

Change to Blue
Creature
 * Disciple of Kangee
 * Fylamarid</c>
 * Grand Architect</c>
 * Indigo Faerie</c> (in addition to its other colors)
 * Metathran Transport</c>
 * Neurok Transmuter</c> (target artifact creature)

Instant
 * Cerulean Wisps</c> (also untaps it)
 * Sea Kings' Blessing</c> (any number of target creatures)
 * Thoughtlace</c> (permanent color change)

Change to Black
Enchantment
 * Darkest Hour</c> (all creatures)
 * Grave Servitude</c>
 * Sinister Strength</c>

Instant
 * Aphotic Wisps</c> (also gains fear)
 * Deathlace</c> (permanent color change)
 * Defiling Tears</c>
 * Nightcreep</c> (all creatures; also all lands become Swamps)
 * Singe</c>
 * <c>Traitor's Clutch</c> (also gains shadow)
 * <c>Touch of Darkness</c> (any number of target creatures)

Change to Red
Instant
 * <c>Chaoslace</c> (permanent color change)
 * <c>Crimson Wisps</c> (also gains haste)
 * <c>Dwarven Song</c> (any number of target creatures)
 * <c>Incite</c>

Change to Green
Creature
 * <c>Aisling Leprechaun</c> (whenever it blocks or becomes blocked by a creature, that creature becomes green)

Instant
 * <c>Lifelace</c> (permanent color change)
 * <c>Viridescent Wisps</c> (also +1/+0)
 * <c>Sylvan Paradise</c> (any number of target creatures)

Change to Colorless
Artifact
 * <c>Mycosynth Lattice</c> (all cards that aren't on the battlefield, spells, and permanents)
 * <c>Thran Lens</c> (all permanents)

Creature
 * <c>Ersatz Gnomes</c>
 * <c>Ghostflame Sliver</c> (all Slivers)

Instant
 * <c>Moonlace</c> (permanent color change)

Change to the color of your choice
Artifact
 * <c>Alchor's Tomb</c>
 * <c>Distorting Lens</c>

Creature
 * <c>Blind Seer</c>
 * <c>Govern the Guildless</c> (Forecast )
 * <c>Painter's Servant</c> (all cards and all permanents)
 * <c>Prismwake Merrow</c>
 * <c>Scuttlemutt</c>
 * <c>Swirling Spriggan</c>
 * <c>Tidal Visionary</c>
 * <c>Vodalian Mystic</c> (target instant or sorcery spell)
 * <c>Wild Mongrel</c>

Enchantment
 * <c>Dream Coat</c>
 * <c>Sisay's Ingenuity</c>
 * <c>Shifting Sky</c>

Instant
 * <c>Prismatic Lace</c>
 * <c>Quickchange</c>
 * <c>Sway of Illusion</c> (any number of target creatures)
 * <c>Sway of Illusion</c> (any number of target creatures)