Kaleidoscorch is a uncommon Sorcery card from Modern Horizons 2 (MH2), collector number 133. Current market price: $0.16 (foil $0.15), TCGplayer market prices via Scryfall.
Converge — Kaleidoscorch deals X damage to any target, where X is the number of colors of mana spent to cast this spell. Flashback {4}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)