Stuck on one suit, would like to change to 2 suits.
The game offers you to play using the following modes:
This means you will have to start a new game and then choose the difficulty from Easy to Medium. However, the 1 Suit is the easiest one and has big chances of completion. Switching to 2 suit games, will increase the difficulty.
Official page: http://www.brainiumstudios.com/app/spider-solitaire