2022-04-29 : Evolving Door's ability instructs you to count the number of colors, but it doesn't track what those colors were. For example, if you sacrifice a creature that is green and no other colors, you'll search for any creature card that is exactly two colors, even if the card you search for isn't green.

2022-04-29 : If you choose to cast the spell, you must cast it as Evolving Door's ability resolves. You cannot wait and cast it later.

2022-04-29 : If you sacrifice a colorless creature, you must search your library for a creature card with exactly one color. If you sacrifice a creature that is all five colors, you won't be able to find any creatures because there are no creature cards in Magic with six colors.

2022-04-29 : You count the colors of the sacrificed creature as it last existed on the battlefield. Notably, if it was a double-faced card or a copy of another creature, that may be different from what its colors are in the graveyard.

2022-04-29 : You must pay all costs for a spell you cast this way.