SetLightGridColor — Set the color for grid lines and data label lines
$plot->SetLightGridColor($color
)
SetLightGridColor
sets the color used for the X and Y
grid lines.
This color is also used for X data label lines, if enabled with
SetDrawXDataLabelLines,
and for Y data label lines, if enabled with
SetDrawYDataLabelLines.
The default color is gray.
This function, not SetGridColor, sets the color for the grid lines.