Your search for "Prismatic Lens 264" revealed the following:
Prismatic Lens (OTC) from Outlaws of Thunder Junction Commander, available at 401 Games Canada. Rarity: Uncommon Finish: Normal Artist: Alan Pollack Card Text:T: Add C.1, T: Add one mana of any color.
Prismatic Lens (Foil) (TSP) from Time Spiral, available at 401 Games Canada. Rarity: Common Finish: Foil Artist: Alan Pollack Card Text:T: Add 1 to your mana pool.1, T: Add one mana of any color to your mana pool.
Prismatic Lens (EMA) from Eternal Masters, available at 401 Games Canada. Rarity: Uncommon Finish: Normal Artist: Alan Pollack Card Text:T: Add C to your mana pool.1, T: Add one mana of any color to your mana pool.