Hydroblast

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

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.)

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.

Chill

Sword of the Animist

Equipped creature gets +1/+1.
Whenever equipped creature attacks, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Equip {2}

Narwhal

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."

Cerulean Drake

Flying
Protection from red (This creature can't be blocked, targeted, dealt damage, enchanted, or equipped by anything red.)
Sacrifice Cerulean Drake: Counter target spell that targets you.

Coastal Piracy

Whenever a creature you control deals combat damage to an opponent, you may draw a card.

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.

Hibernation

Return all green permanents to their owners' hands.

Douse

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.

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.)

Baleful Stare

Target opponent reveals their hand. You draw a card for each Mountain and red card in it.

Lotus Petal

{T}, Sacrifice Lotus Petal: Add one mana of any color.

Insight

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

Sea Sprite

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.)

Riptide

Blue Elemental Blast

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

Withering Gaze

Target opponent reveals their hand. You draw a card for each Forest and green card in it.

Vodalian Mystic

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

Spectral Shift

Choose one —
• Change the text of target spell or permanent by replacing all instances of one basic land type with another. (This effect lasts indefinitely.)
• Change the text of target spell or permanent by replacing all instances of one color word with another. (This effect lasts indefinitely.)
Entwine {2} (Choose both if you pay the entwine cost.)

Tidal Visionary

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

Sway of Illusion

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

Oraxid

Sol Ring

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."

Training Grounds

Activated abilities of creatures you control cost {2} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Jaded Response

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

Extraplanar Lens

Imprint — When Extraplanar Lens enters, you may exile target land you control.
Whenever a land with the same name as the exiled card is tapped for mana, its controller adds one mana of any type that land produced.

Reconnaissance Mission

Whenever a creature you control deals combat damage to a player, you may draw a card.
Cycling {2} ({2}, Discard this card: Draw a card.)

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.)

Mind Bend

Change the text of target permanent by replacing all instances of one color word with another or one basic land type with another. (For example, you may change "nonblack creature" to "nongreen creature" or "forestwalk" to "islandwalk." This effect lasts indefinitely.)

Nyx Lotus

Nyx Lotus enters tapped.
{T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Blind Seer

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

Weatherseed Faeries

Flash Flood

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

Bident of Thassa

Whenever a creature you control deals combat damage to a player, you may draw a card.
{1}{U}, {T}: Creatures your opponents control attack this turn if able.

Throne of Eldraine

As Throne of Eldraine enters, choose a color.
{T}: Add four mana of the chosen color. Spend this mana only to cast monocolored spells of that color.
{3}, {T}: Draw two cards. Spend only mana of the chosen color to activate this ability.

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.

Essence Leak

Enchant permanent
As long as enchanted permanent is red or green, it has "At the beginning of your upkeep, sacrifice this permanent unless you pay its mana cost."

Mourner's Shield

Imprint — When Mourner's Shield enters, you may exile target card from a graveyard.
{2}, {T}: Prevent all damage that would be dealt this turn by a source of your choice that shares a color with the exiled card.

Wash Out

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

Flashfreeze

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Quickchange

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

Future Sight

Play with the top card of your library revealed.
You may play lands and cast spells from the top of your library.

Gainsay

Prismatic Lace

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

Aven Smokeweaver

Well-Laid Plans

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

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.)

Illusionist's Bracers

Whenever an ability of equipped creature is activated, if it isn't a mana ability, copy that ability. You may choose new targets for the copy.
Equip {3}

Island

Coast Watcher

Cerulean Wyvern

Nykthos, Shrine to Nyx

{T}: Add {C}.
{2}, {T}: Choose a color. Add an amount of mana of that color equal to your devotion to that color. (Your devotion to a color is the number of mana symbols of that color in the mana costs of permanents you control.)

Distorting Lens

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

Caged Sun

As Caged Sun enters, choose a color.
Creatures you control of the chosen color get +1/+1.
Whenever a land's ability causes you to add one or more mana of the chosen color, add one additional mana of that color.

Ancient Tomb

{T}: Add {C}{C}. Ancient Tomb deals 2 damage to you.

Omen Hawker

{T}: Add {C}{U}. Spend this mana only to activate abilities.

Shifting Sky

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

Enduring Curiosity

Flash
Whenever a creature you control deals combat damage to a player, draw a card.
When Enduring Curiosity dies, if it was a creature, return it to the battlefield under its owner's control. It's an enchantment. (It's not a creature.)