When Threefold Signal enters, scry 3.
Each spell you cast that’s exactly three colors has replicate . (When you cast it, copy it for each time you paid its replicate cost. You may choose new targets for the copies. A copy of a permanent spell becomes a token.)
If you cast a spell that already has replicate while you have this permanent on the battlefield, the spell will have two replicate abilities: one with a replicate cost as printed on it, and one with a replicate cost of {3}. You may use either ability, or both abilities, to replicate the spell.
Random a card of Magic: The Gathering (MTG), but you can also roll the D20 dice, random a Planeswalker, have fun with the random rules and more.