Conditional-Formatting.md

Range of numbers

var workbook = new XLWorkbook();
var ws = workbook.AddWorksheet("Sheet1");

ws.FirstCell().SetValue(1)
  .CellBelow().SetValue(1)
  .CellBelow().SetValue(2)
  .CellBelow().SetValue(3)
  .CellBelow().SetValue(4);

ws.RangeUsed().AddConditionalFormat().WhenBetween(2, 3)
  .Fill.SetBackgroundColor(XLColor.Red);

Color Scale

var workbook = new XLWorkbook();
var ws = workbook.AddWorksheet("Sheet1");

ws.FirstCell().SetValue(1)
  .CellBelow().SetValue(1)
  .CellBelow().SetValue(2)
  .CellBelow().SetValue(3)
  .CellBelow().SetValue(4);

ws.RangeUsed().AddConditionalFormat().ColorScale()
  .LowestValue(XLColor.Red)
  .Midpoint(XLCFContentType.Percent, 50, XLColor.Yellow)
  .HighestValue(XLColor.Green);

var workbook = new XLWorkbook();
var ws = workbook.AddWorksheet("Sheet1");

ws.FirstCell().SetValue(1)
  .CellBelow().SetValue(1)
  .CellBelow().SetValue(2)
  .CellBelow().SetValue(3)
  .CellBelow().SetValue(4);

ws.RangeUsed().AddConditionalFormat().IconSet(XLIconSetStyle.ThreeTrafficLights2)
  .AddValue(XLCFIconSetOperator.EqualOrGreaterThan, 0, XLCFContentType.Number)
  .AddValue(XLCFIconSetOperator.EqualOrGreaterThan, 2, XLCFContentType.Number)
  .AddValue(XLCFIconSetOperator.EqualOrGreaterThan, 3, XLCFContentType.Number);

var workbook = new XLWorkbook();
var ws = workbook.AddWorksheet("Sheet1");

ws.FirstCell().SetValue(1)
  .CellBelow().SetValue(1)
  .CellBelow().SetValue(2)
  .CellBelow().SetValue(3)
  .CellBelow().SetValue(4);

ws.RangeUsed().AddConditionalFormat().DataBar(XLColor.Red)
  .LowestValue()
  .HighestValue();

Using Formulas
Just put your match with an = sign. e.g.

.AddConditionalFormat().WhenEquals("=B1")

If you need to start the string with an equal sign then put the entire string between quotes ("\"=Hello\"")