Changing Excel Gridline Color
In previous versions of Excel, you had two choices for gridline color: gray and invisible. In Excel 2007, you can make the gridlines any of 56 colors. (It is not clear why Microsoft went back to a 56-color limit instead of 32-bit color scheme for this feature.)
To change the gridline color, you need to open the Excel Options dialog. Then you choose the Advanced category. Next, you scroll down to the Display Options for This Worksheet section. In the Gridline Color drop-down, you choose a color for the gridlines.
