Shifting Sky

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

Vodalian Mystic

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

Fylamarid

Flying
Fylamarid can't be blocked by blue creatures.
{U}: Target creature becomes blue until end of turn.

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.

Douse

Virtue's Ruin

Distorting Lens

{T}: Target permanent becomes the color 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.")

Darkest Hour

Perish

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

Reality

Illusion

Target spell or permanent becomes the color of your choice until end of turn.

Illusion // Reality

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.

Indigo Faerie

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

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.

Deathgrip

Archelos, Lagoon Mystic

As long as Archelos, Lagoon Mystic is tapped, other permanents enter tapped.
As long as Archelos is untapped, other permanents enter untapped.

Blind Seer

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

Prismatic Lace

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

Scuttlemutt

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