Figure 21: Using two alternating colors between the gridlines [src]
Another option for the grid lines is the possibility to have the area between the grid lines filled with alternating two colors. The example below illustrates this.
In the example above we have also made use of alpha-blending (requires GD 2.x or higher). By default the filled grid lines are disabled. To enable this style you have to call the Grid::SetFill() method.