Harmony At Wits End

If you would lose unspent mana, that mana
becomes black instead.
At the beginning of your precombat main
phase, look at the top card of your library.
You may reveal that card if it has three or
more colored mana symbols in its mana cost.
If you do, add three mana in any combination
of its colors and put it into your hand. If you
don’t reveal it, put it into your hand.