gcSpreadSheet1.Sheets[0].Cells[0, 0].Value = 1;
gcSpreadSheet1.Sheets[0].Cells[1, 0].Value = 10;
gcSpreadSheet1.Sheets[0].Cells[2, 0].Value = 6;
gcSpreadSheet1.Sheets[0].Cells[3, 0].Value = -3;
GrapeCity.Windows.SpreadSheet.Data.DataBarRule test = new GrapeCity.Windows.SpreadSheet.Data.DataBarRule();
test.Color = Colors.Magenta;
test.ShowBarOnly = true;
test.Ranges = new GrapeCity.Windows.SpreadSheet.Data.CellRange[] { new GrapeCity.Windows.SpreadSheet.Data.CellRange(0, 0, 5, 1) };
gcSpreadSheet1.Sheets[0].ConditionalFormats.AddRule(test);