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.)

Might of the Nephilim

Target creature gets +2/+2 until end of turn for each of its colors.

Civic Saber

Equipped creature gets +1/+0 for each of its colors.
Equip {1}

Tam, Mindful First-Year

Each other creature you control has hexproof from each of its colors.
{T}: Target creature you control becomes all colors until end of turn.

Glister Bairn

Vivid — At the beginning of combat on your turn, another target creature you control gets +X/+X until end of turn, where X is the number of colors among permanents you control.

Foraging Wickermaw

When this creature enters, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{1}: Add one mana of any color. This creature becomes that color until end of turn. Activate only once each turn.

Thornwatch Scarecrow

This creature has wither as long as you control a green creature. (It deals damage to creatures in the form of -1/-1 counters.)
This creature has vigilance as long as you control a white creature.

Aurora Awakener

Trample
Vivid — When this creature enters, reveal cards from the top of your library until you reveal X permanent cards, where X is the number of colors among permanents you control. Put any number of those permanent cards onto the battlefield, then put the rest of the revealed cards on the bottom of your library in a random order.

Blind Seer

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

Fang Skulkin

{2}: Target black creature gains wither until end of turn. (It deals damage to creatures in the form of -1/-1 counters.)

Threefold Signal

When this artifact enters, scry 3.
Each spell you cast that's exactly three colors has replicate {3}. (When you cast it, copy it for each time you paid its replicate cost. You may choose new targets for the copies. A copy of a permanent spell becomes a token.)

Case of the Shattered Pact

When this Case enters, search your library for a basic land card, reveal it, put it into your hand, then shuffle.
To solve — There are five colors among permanents you control. (If unsolved, solve at the beginning of your end step.)
Solved — At the beginning of combat on your turn, target creature you control gains flying, double strike, and vigilance until end of turn.

Dream Coat

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

Insight

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

Prismwake Merrow

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

Scrapbasket

{1}: This creature becomes all colors until end of turn.

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 this creature.

Bring to Light

Converge — Search your library for a creature, instant, or sorcery card with mana value less than or equal to the number of colors of mana spent to cast this spell, exile that card, then shuffle. You may cast that card without paying its mana cost.

Elemental Spectacle

Vivid — Create a number of 5/5 red and green Elemental creature tokens equal to the number of colors among permanents you control. Then you gain life equal to the number of creatures you control.

Brilliant Spectrum

Converge — Draw X cards, where X is the number of colors of mana spent to cast this spell. Then discard two cards.

Roilmage's Trick

Converge — Creatures your opponents control get -X/-0 until end of turn, where X is the number of colors of mana spent to cast this spell.
Draw a card.

Prismatic Lace

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

Quickchange

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

Omo, Queen of Vesuva

Whenever Omo enters or attacks, put an everything counter on each of up to one target land and up to one target creature.
Each land with an everything counter on it is every land type in addition to its other types.
Each nonland creature with an everything counter on it is every creature type.

Blazethorn Scarecrow

This creature has haste as long as you control a red creature.
This creature has wither as long as you control a green creature. (It deals damage to creatures in the form of -1/-1 counters.)

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.)

Shyft

At the beginning of your upkeep, you may have this creature become the color or colors of your choice. (This effect lasts indefinitely.)

Leyline Immersion

Enchant legendary creature
Enchanted creature has ward {2} and "{T}: Add five mana in any combination of colors. Spend this mana only to cast spells."

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.)

Snake Pit

Whenever an opponent casts a blue or black spell, you may create a 1/1 green Snake creature token.

Elemental Resonance

Enchant permanent
At the beginning of your first main phase, add mana equal to enchanted permanent's mana cost. (Mana cost includes color. If a mana symbol has multiple colors, choose one.)

Indigo Faerie

Flying
{U}: Target permanent becomes blue in addition to its other colors until end of turn.

Watchwing Scarecrow

This creature has vigilance as long as you control a white creature.
This creature has flying as long as you control a blue creature.

Prismatic Undercurrents

Vivid — When this enchantment enters, search your library for up to X basic land cards, where X is the number of colors among permanents you control. Reveal those cards, put them into your hand, then shuffle.
You may play an additional land on each of your turns.

Wash Out

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

Fallaji Wayfarer

Fallaji Wayfarer is all colors. This ability doesn't affect its color identity. (It can be in any deck whose commander's color identity includes green.)
Multicolored spells you cast have convoke. (Your creatures can help cast those spells. Each creature you tap while casting a multicolored spell pays for {1} or one mana of a color that creature is.)

Prismabasher

Trample
Vivid — When this creature enters, up to X target creatures you control get +X/+X until end of turn, where X is the number of colors among permanents you control.

Wingrattle Scarecrow

This creature has flying as long as you control a blue creature.
This creature has persist as long as you control a black creature. (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Shell Skulkin

{3}: Target blue creature gains shroud until end of turn. (It can't be the target of spells or abilities.)

Shinestriker

Flying
Vivid — When this creature enters, draw cards equal to the number of colors among permanents you control.