Chameleon Spirit

As Chameleon Spirit enters, choose a color.
Chameleon Spirit's power and toughness are each equal to the number of permanents of the chosen color your opponents control.

Compost

Whenever a black card is put into an opponent's graveyard from anywhere, you may draw a card.

Boon Reflection

If you would gain life, you gain twice that much life instead.

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.

Serra Avatar

Serra Avatar's power and toughness are each equal to your life total.
When Serra Avatar is put into a graveyard from anywhere, shuffle it into its owner's library.

Shifting Sky

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

Treva, the Renewer

Flying
Whenever Treva, the Renewer deals combat damage to a player, you may pay {2}{W}. If you do, choose a color, then you gain 1 life for each permanent of that color.

Flurry of Wings

Create X 1/1 white Bird Soldier creature tokens with flying, where X is the number of attacking creatures.

Sway of Illusion

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

Pygmy Kavu

When Pygmy Kavu enters, draw a card for each black creature your opponents control.