Prismatic Lens

Sunburst (This comes into play with a charge counter
on it for each color of mana spent to cast it.)
{t}: Add one mana of any colour equal to the
number of charge counters on Prismatic Lens,
then remove one charge counter from Prismatic
Lens.
During your end-step, if Prismatic Lens has no
charge counters on it, return it to your hand.
A glimpse of endless possibilities.