Set and format the Value Axis Display Units Label
Display the value axis Display Units Label and set the font color to red , the fill color to AntiqueWhite and the border color to blue.
Output: DisplayUnitsLabelFormat.xlsx
var workbook = new Workbook();
var worksheet = workbook.Worksheets[0];
worksheet.GetRange("J1:L1").SetValue(new[] { "Series 1", "Series 2", "Series 3" });
worksheet.GetRange("I2:I5").SetValue(new[] { "Point 1", "Point 2", "Point 3", "Point 4" });
worksheet.GetRange("J2:J5").SetValue(new[] { 2, 4, 6, 8 });
worksheet.GetRange("K2:K5").SetValue(new[] { 4, 3, 2, 1 });
worksheet.GetRange("L2:L5").SetValue(new[] { 2, 1, -1, -2 });
var chart1 = worksheet.Charts.Add<BarChart>("A1");
chart1.ChartType = ChartType.Column;
chart1.Size.HeightInches = 2.5;
chart1.Size.WidthInches = 3.5;
chart1.DataSource = "Sheet1!$I$1:$L$5";
chart1.ValueAxis.DisplayUnitMultiplier = 100;
chart1.ValueAxis.DisplayUnitsLabel = new DisplayUnitsLabel();
chart1.ValueAxis.DisplayUnitsLabel.FormattedText.Font.Color = Color.Red;
chart1.ValueAxis.DisplayUnitsLabel.Fill.SolidColor = Color.AntiqueWhite;
chart1.ValueAxis.DisplayUnitsLabel.Border.Color = Color.Blue;
workbook.SaveAs("DisplayUnitsLabelFormat.xlsx");