The five colors in magic are White, Blue, Black, Red, and Green
There are some obvious applications here for existing Auras decks
Its more of an unspoken agreement, and you may find that if you step over it in a casual game, itll be considered a faux pas
If an army of Angels, Spirits, and Pegasuses isnt enough for you, I present you with a faster option
Instant Color tag templates(None) Jaheira's Respite Search your library for up to X basic land cards, where X is the number of creatures attacking you, put those cards onto the battlefield tapped, then shuffle
The main reason we've shifted away from this is the realization that rarity was not the barrier than Richard initially envisioned