Mirran Crusader

Double strike, protection from black and from green

Tidal Visionary

{T}: Target creature becomes the color of your choice until end of turn.

Auriok Champion

Protection from black and from red
Whenever another creature enters, you may gain 1 life.

Whim of Volrath

Buyback {2} (You may pay an additional {2} as you cast this spell. If you do, put this card into your hand as it resolves.)
Change the text of target permanent by replacing all instances of one color word with another or one basic land type with another until end of turn. (For example, you may change "nonred creature" to "nongreen creature" or "plainswalk" to "swampwalk.")

Dromar, the Banisher

Flying
Whenever Dromar deals combat damage to a player, you may pay {2}{U}. If you do, choose a color, then return all creatures of that color to their owners' hands.

Prismwake Merrow

Flash
When this creature enters, target permanent becomes the color or colors of your choice until end of turn.

Quickchange

Target creature becomes the color or colors of your choice until end of turn.
Draw a card.

Light of Day

Deathgrip

Llawan, Cephalid Empress

When Llawan enters, return all blue creatures your opponents control to their owners' hands.
Your opponents can't cast blue creature spells.

Swirl the Mists

As this enchantment enters, choose a color word.
All instances of color words in the text of spells and permanents are changed to the chosen color word.

Blue Elemental Blast

Choose one —
• Counter target red spell.
• Destroy target red permanent.

Sword of Feast and Famine

Equipped creature gets +2/+2 and has protection from black and from green.
Whenever equipped creature deals combat damage to a player, that player discards a card and you untap all lands you control.
Equip {2}

Blind Seer

{1}{U}: Target spell or permanent becomes the color of your choice until end of turn.

Vodalian Mystic

{T}: Target instant or sorcery spell becomes the color of your choice.

Glamerdye

Change the text of target spell or permanent by replacing all instances of one color word with another.
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

Pentarch Paladin

Flanking (Whenever a creature without flanking blocks this creature, the blocking creature gets -1/-1 until end of turn.)
As this creature enters, choose a color.
{W}{W}, {T}: Destroy target permanent of the chosen color.

Hydroblast

Choose one —
• Counter target spell if it's red.
• Destroy target permanent if it's red.

Tidal Control

Cumulative upkeep {2} (At the beginning of your upkeep, put an age counter on this permanent, then sacrifice it unless you pay its upkeep cost for each age counter on it.)
Pay 2 life or {2}: Counter target red or green spell. Any player may activate this ability.

Crystal Spray

Change the text of target spell or permanent by replacing all instances of one color word with another or one basic land type with another until end of turn.
Draw a card.

Wrath of Marit Lage

When this enchantment enters, tap all red creatures.
Red creatures don't untap during their controllers' untap steps.

Painter's Servant

As this creature enters, choose a color.
All cards that aren't on the battlefield, spells, and permanents are the chosen color in addition to their other colors.

Sisay's Ingenuity

Enchant creature
When this Aura enters, draw a card.
Enchanted creature has "{2}{U}: Target creature becomes the color of your choice until end of turn."

Scuttlemutt

{T}: Add one mana of any color.
{T}: Target creature becomes the color or colors of your choice until end of turn.

Story Circle

As this enchantment enters, choose a color.
{W}: The next time a source of your choice of the chosen color would deal damage to you this turn, prevent that damage.

Sway of Illusion

Any number of target creatures become the color of your choice until end of turn.
Draw a card.

Shifting Sky

As this enchantment enters, choose a color.
All nonland permanents are the chosen color.

Alter Reality

Change the text of target spell or permanent by replacing all instances of one color word with another. (This effect lasts indefinitely.)
Flashback {1}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Perish

Destroy all green creatures. They can't be regenerated.

Blood Baron of Vizkopa

Lifelink, protection from white and from black
As long as you have 30 or more life and an opponent has 10 or less life, this creature gets +6/+6 and has flying.

Douse

Dread of Night

Virtue's Ruin

Govern the Guildless

Gain control of target monocolored creature.
Forecast — {1}{U}, Reveal this card from your hand: Target creature becomes the color or colors of your choice until end of turn. (Activate only during your upkeep and only once each turn.)

Sphinx of the Steel Wind

Flying, first strike, vigilance, lifelink, protection from red and from green

Distorting Lens

{T}: Target permanent becomes the color of your choice until end of turn.

Eight-and-a-Half-Tails

{1}{W}: Target permanent you control gains protection from white until end of turn.
{1}: Target spell or permanent becomes white until end of turn.