Counterspell

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.

Dream Coat

Enchant creature
{0}: Enchanted creature becomes the color or colors of your choice. Activate only once each turn.

Quickchange

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

Kumena's Awakening

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
At the beginning of your upkeep, each player draws a card. If you have the city's blessing, instead only you draw a card.

Tidal Visionary

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

Pongify

Destroy target creature. It can't be regenerated. Its controller creates a 3/3 green Ape creature token.

Reality Shift

Exile target creature. Its controller manifests the top card of their library. (That player puts the top card of their library onto the battlefield face down as a 2/2 creature. If it's a creature card, it can be turned face up any time for its mana cost.)

Talrand, Sky Summoner

Whenever you cast an instant or sorcery spell, create a 2/2 blue Drake creature token with flying.

Merchant Scroll

Search your library for a blue instant card, reveal that card, put it into your hand, then shuffle.

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Rapid Hybridization

Destroy target creature. It can't be regenerated. That creature's controller creates a 3/3 green Frog Lizard creature token.

Wash Out

Return all permanents of the color of your choice to their owners' hands.

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."

Scuttlemutt

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

King Crab

{1}{U}, {T}: Put target green creature on top of its owner's library.

Sleight of Mind

Change the text of target spell or permanent by replacing all instances of one color word with another. (For example, you may change "target black spell" to "target blue spell." This effect lasts indefinitely.)

Douse

Trophy Mage

When Trophy Mage enters, you may search your library for an artifact card with mana value 3, reveal it, put it into your hand, then shuffle.

Gainsay

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.)

Riptide

Out of the Way

This spell costs {2} less to cast if it targets a green permanent.
Return target nonland permanent an opponent controls to its owner's hand.
Draw a card.

Well-Laid Plans

Prevent all damage that would be dealt to a creature by another creature if they share a color.

Dissipation Field

Whenever a permanent deals damage to you, return it to its owner's hand.

Jaded Response

Counter target spell if it shares a color with a creature you control.

Prismatic Lace

Target permanent becomes the color or colors of your choice. (This effect lasts indefinitely.)

Heartstone

Activated abilities of creatures cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Trinket Mage

When Trinket Mage enters, you may search your library for an artifact card with mana value 1 or less, reveal that card, put it into your hand, then shuffle.

Flash Flood

Choose one —
• Destroy target red permanent.
• Return target Mountain to its owner's hand.

Wrath of Marit Lage

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

Blue Elemental Blast

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

Master of Waves

Protection from red
Elemental creatures you control get +1/+1.
When Master of Waves enters, create a number of 1/0 blue Elemental creature tokens equal to your devotion to blue. (Each {U} in the mana costs of permanents you control counts toward your devotion to blue.)

Aether Gust

Choose target spell or permanent that's red or green. Its owner puts it on their choice of the top or bottom of their library.

Sway of Illusion

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

Willbreaker

Whenever a creature an opponent controls becomes the target of a spell or ability you control, gain control of that creature for as long as you control Willbreaker.

Hauken's Insight

At the beginning of your upkeep, exile the top card of your library face down. You may look at that card for as long as it remains exiled.
Once during each of your turns, you may play a land or cast a spell from among the cards exiled with this permanent without paying its mana cost.

Jacob Hauken, Inspector

{T}: Draw a card, then exile a card from your hand face down. You may look at that card for as long as it remains exiled. You may pay {4}{U}{U}. If you do, transform Jacob Hauken, Inspector.

Jacob Hauken, Inspector // Hauken's Insight

Distorting Lens

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

Sky Diamond

Shifting Sky

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

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Cowardice

Whenever a creature becomes the target of a spell or ability, return that creature to its owner's hand. (It won't be affected by the spell or ability.)

Prismwake Merrow

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

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.")

Hibernation

Return all green permanents to their owners' hands.

Hydroblast

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

Blind Seer

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

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.)

Sol Ring

Drift of Phantasms

Defender (This creature can't attack.)
Flying
Transmute {1}{U}{U} ({1}{U}{U}, Discard this card: Search your library for a card with the same mana value as this card, reveal it, put it into your hand, then shuffle. Transmute only as a sorcery.)

Dismiss into Dream

Each creature your opponents control is an Illusion in addition to its other types and has "When this creature becomes the target of a spell or ability, sacrifice it."

Insight

Whenever an opponent casts a green spell, you draw a card.

Sapphire Medallion

Blue spells you cast cost {1} less to cast.

Vodalian Mystic

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

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.

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.)

Flashfreeze

Isochron Scepter

Imprint — When Isochron Scepter enters, you may exile an instant card with mana value 2 or less from your hand.
{2}, {T}: You may copy the exiled card. If you do, you may cast the copy without paying its mana cost.

Dictate of Kruphix

Flash (You may cast this spell any time you could cast an instant.)
At the beginning of each player's draw step, that player draws an additional card.

Treasure Cruise

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Draw three cards.

Scry 1. (Look at the top card of your library. You may put that card on the bottom.)
Draw a card.