1 deck. Easy. 2 redeals.
Rainbow Solitaire uses 52 cards (1 deck). 13 cards are counted out from the deck of 52 cards. The top card is open. This is the reserve pile. The next four open cards are tableau piles. The next card is placed above. This will be the starter card of the foundation piles. The three other cards of the same rank will be placed next to it during play as soon as they are available.
You may build tableau piles in descending order, alternating suit color. Only the top card of each tableau pile and the reserve pile is available for play on the foundation piles. One card or group of cards in the proper sequence can be moved to another tableau pile. Empty tableau pile is immediately filled up with a card from the reserve pile if possible, then by any card.
You have two redeals.
Rainbow Solitaire is similar to Canfield Solitaire except that in Rainbow Solitaire you turn cards from the stock one at a time and you have only 2 redeals.