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.

Wrath of Marit Lage

When Wrath of Marit Lage enters, tap all red creatures.
Red creatures don't untap during their controllers' untap steps.

Sway of Illusion

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

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.

Swirl the Mists

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

Blind Seer

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

Virtue's Ruin

Hydroblast

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

Llawan, Cephalid Empress

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

Blue Elemental Blast

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

Pentarch Paladin

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

Govern the Guildless

Gain control of target monocolored creature.
Forecast — {1}{U}, Reveal Govern the Guildless 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.)

Douse

Shifting Sky

As Shifting Sky enters, choose a color.
All nonland permanents are the chosen color.

Perish

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

Distorting Lens

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

Tidal Visionary

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

Story Circle

As Story Circle 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.

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.)

Dromar, the Banisher

Flying
Whenever Dromar, the Banisher 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.

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}

Auriok Champion

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

Vodalian Mystic

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

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.)

Prismwake Merrow

Flash
When Prismwake Merrow 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.

Scuttlemutt

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

Deathgrip

Painter's Servant

As Painter's Servant 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.

Sphinx of the Steel Wind

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

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.

Sisay's Ingenuity

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

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, Blood Baron of Vizkopa gets +6/+6 and has flying.

Dread of Night

Mirran Crusader

Double strike, protection from black and from green

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.")