Prismatic Lace

Color is the substrate underneath protection, color-hosers, and a whole layer of older targeting rules, and this is one-mana, instant-speed access to that substrate against any permanent, lands and artifacts included. The card does nothing to the board by itself, yet it rewrites one of the most foundational attributes a permanent has. Every application runs through the corners of the rules. Recolor an opponent's creature into the teeth of a color-specific kill spell so it suddenly answers something it could not touch before. Make your own permanent the wrong color for an enemy's protection-from clause, or paint it to dodge a color-targeted removal effect. The price of that flexibility is that it solves a problem that only sometimes exists: most boards do not care what color anything is, so the spell asks you to find the situation where color is load-bearing before it earns its slot. It treats color itself as a manipulable resource rather than a fixed label, the same conceptual lineage as Crystal Spray and the various "becomes the color of your choice" riders printed since. The indefinite duration is the detail that elevates it past a one-turn nudge: this is permanent reclassification, not a temporary trick, and on the right board that reclassification settles the game.