3Who said sudoku have to be black and white? These 180 multihued puzzles come in a rainbow of glorious colors and patterns that enhance the fun. Although they begin with the standard 9 9 grid and follow the basic rules, each sudoku offers a fresh twist to tradition: perhaps every red square must contain a different number, or a puzzle may look like a jigsaw. It's the perfect collection for solvers who enjoy a challenge that's way out of the ordinary.