Set the following options as desired:
Color specifies the color of the grid lines.
Click the color swatch and select a color from the color picker, or type a hexadecimal number in the text box.
Show Grid makes the grid visible in Design view.
Snap to Grid makes page elements snap to the lines of the grid.
Spacing controls how far apart the grid lines are.
Enter a number in the text box and select Pixels, Inches, or Centimeters from the menu.
Display specifies whether the grid lines appear as lines or dots.