The First Sliver

Cascade (When you cast this spell, 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.)
Sliver spells you cast have cascade.

Gemhide Sliver

All Slivers have "{T}: Add one mana of any color."

Timeless Lotus

Timeless Lotus enters tapped.
{T}: Add {W}{U}{B}{R}{G}.

Manaweft Sliver

Sliver creatures you control have "{T}: Add one mana of any color."