Mirrodin's Core

The fixing here comes with an upfront tax most filter lands refuse to charge: before this can produce a color, you have to spend a turn doing nothing but banking a charge counter, and that stored charge takes a separate tap to redeem. Every mode here competes for the same single tap. Tap for colorless and you stand still; tap to charge and you stand still again; only on a later turn does the tap-and-remove finally hand you the any-color mana you actually wanted. That windup is the price for unconditional five-color fixing on a land that costs nothing and enters untapped. This is one of the early designs that converts time into color, trading the immediacy of a fetch-and-shock manabase for a payment plan, and the choice it forces is which job the land does on a given turn rather than whether it produces anything at all. The counters do make it sturdier than a one-use filter, since the land can never be fully spent; a slow opening lets you stockpile several charges against a long game. But that resilience is bounded by the single tap it gets each turn: you draw on the reserve one charge at a time, never cashing it out in a single burst. The stockpile is insurance, not a payload, and the deck that wants it is one with turns to spare and no better use for the early taps.