Lace

The laces are a rare cycle of five instants that appeared in the Alpha through Fourth Edition core sets. Each change a spell or permanent to a particular color. They were originally interrupts.

Description
Richard Garfield derived "lace" from the Wizards of the Coast roleplaying game The Primal Order. In that game deities can "lace" an object or spell with primal energy, imbuing it with a portion of their own divine nature.

The originals
In color wheel order by color,
 * Purelace
 * Thoughtlace
 * Deathlace
 * Chaoslace
 * Lifelace

They weren't highly sought after rares by any means and were thought to be novelty cards use primarily to change a card so as not to be able to be blocked by a creature with protection from a particular color. Thoughtlace and Chaoslace were used more often in conjunction with Blue Elemental Blast and Red Elemental Blast.

Reboots
Mark Rosewater considers the color-wash instants of Legends as another spin on Laces: each of these uncommon instants has a casting cost of M and the effect of changing the color of any number of target creatures to a particular color until end of turn Heaven's Gate, Sea Kings' Blessing</c>, Touch of Darkness</c>, Dwarven Song</c>, and Sylvan Paradise</c>. These were even less popular than the originals.

Prismatic Lace</c> from Mirage is an improved version of the original cycle, that is able to change a permanent (but not a spell) to a color of the caster's choice. Moonlace</c> from the time twisting set Time Spiral turned a spell or permanent colorless. All of the color changes are permanent.