Fill in the grid so that every row, every column, and every 3x3 box contains the digits 1 through 9. Red cells must contain digits 1, 2 or 3, blue cells must contain digits 4, 5 or 6, and yellow cells must contain digits 7, 8 or 9.

Fill in the grid so that every row, every column, and every 3x3 box contains the digits 1 through 9. Red cells must contain digits 1, 2 or 3, blue cells must contain digits 4, 5 or 6, and yellow cells must contain digits 7, 8 or 9.