Create a 9-by-9 grid on a sheet of paper, using a ruler to make straight lines. Each square should be about one inch by one inch.
Label the left vertical side of the grid with the letters A through I, and the top horizontal side with the numbers 1 through 9. This will provide an easy way to identify which square you need to color.
Choose a marker to be your base color, let's say red, and fill in every other square to create a standard color and white checkerboard pattern.
Choose two colors, for example, blue and purple, and color in the white squares, alternating the colors between the white squares.
For example: Square A1 is red, A2 is blue, A3 is red, A4 is purple, A5 is red, A6 is blue, and so on.