Urza's Power Plant

{T}: Add {C}. If you control an Urza's Mine and an Urza's Tower, add {C}{C} instead.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Zhulodok, Void Gorger

Colorless spells you cast from your hand with mana value 7 or greater have "Cascade, cascade." (When you cast one, exile cards from the top of your library until you exile a nonland card that costs less. You may cast it without paying its mana cost. Put the exiled cards on the bottom in a random order. Then do it again.)

Patchwork Banner

As Patchwork Banner enters, choose a creature type.
Creatures you control of the chosen type get +1/+1.
{T}: Add one mana of any color.

Sol Ring

Worn Powerstone

Worn Powerstone enters tapped.
{T}: Add {C}{C}.

Dreamstone Hedron

{T}: Add {C}{C}{C}.
{3}, {T}, Sacrifice Dreamstone Hedron: Draw three cards.

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Reliquary Tower

Urza's Mine

{T}: Add {C}. If you control an Urza's Power-Plant and an Urza's Tower, add {C}{C} instead.

Urza's Tower

{T}: Add {C}. If you control an Urza's Mine and an Urza's Power-Plant, add {C}{C}{C} instead.

Eye of Ugin

Colorless Eldrazi spells you cast cost {2} less to cast.
{7}, {T}: Search your library for a colorless creature card, reveal it, put it into your hand, then shuffle.

Shrine of the Forsaken Gods

{T}: Add {C}.
{T}: Add {C}{C}. Spend this mana only to cast colorless spells. Activate only if you control seven or more lands.