Moresso, Infuser of Light is all colors.
Hexproof from monocolored
Whenever you cast a spell with four or more mana symbols in its mana cost, add four mana of different colors. This ability triggers only once each turn.

Target opponent discards their hand, then draws seven cards. You discard your hand, then exile the top seven cards of that player's library. You may play those cards as long as they remain exiled, and mana of any type can be spent to cast them.