mtg multicolored cards count as both colors Can someone explain the rules around “all colors” and multicolor cards?

The Modern Horizons 3 Tricky Terrain Commander Deck includes 1 deck of 100 Magic cards (2 Traditional Foil Legendary cards, 98 nonfoil cards), a 2-card Collector Booster Sample Pack (contains 1 Traditional Foil or nonfoil alt-frame card of rarity Rare or higher and 1 Traditional Foil alt-frame Common or Uncommon card), 1 foil-etched Display Commander (a thick cardstock copy of the commander card with foil etched into the cards border and art), 10 double-sided tokens, 1 deck box (can hold 100 sleeved cards), 1 Life Wheel, 1 strategy insert, and 1 reference card

9: Search your graveyard and library for any number of red instant and/or sorcery cards, exile them, then shuffle

When Casal enters, search your library for a Forest card, put it onto the battlefield tapped, then shuffle

Death Bomb from Planeshift

TheCommanderseries is a great entry point for players interested in the format

COUNTLESS PATHS TO VICTORY