[]
Gets the format of the gridlines.
IChartFormat Format { get; }
ReadOnly Property Format As IChartFormat
worksheet.Range["A1:B3"].Value = new object[,] {
{"Month", "Sales"},
{"Jan", 10},
{"Feb", 15}
};
IShape shape = worksheet.Shapes.AddChart(ChartType.ColumnClustered, 0, 0, 300, 200);
shape.Chart.SeriesCollection.Add(worksheet.Range["A1:B3"]);
IGridlines gridlines = shape.Chart.Axes.Item(AxisType.Value).MajorGridlines;
IChartFormat format = gridlines.Format;
format.Line.Color.RGB = Color.Blue;