Normal sudoku rules apply. Digits a knightâs move away cannot be the same. Colors used in this puzzle are blue (b), white (w) and red (unshaded). The squares outside the grid indicate the order of the runs of contiguous cells that must be shaded the color of the clue. The number in the square indicates the sum of the cells in the run OFF BY 1! There must be at least one unshaded cell between runs of the same color, but that is not required for runs of different colors. All shaded runs are given.