title: NPOI Excel / C# Need formula to programatically change background for conditional formatting
body: <p>I'm using NPOI to programatically create an Excel file. One of the requirements is that it needs to be able to change the background of cells based on values - green for good numbers, red for bad, etc.  I have everything working perfectly and can create formulas...but I cannot for the life of me find a formula that shows how to change background color. No matter how I try to google for the answer, everything just wants to show how to open Excel and use the conditional formatting wizard.  I'm overlooking something?  Is there a way I can see the formula that the conditional formatting wizard created and just copy and paste it into my code?</p>
  
  <p>Below is a sample I set up to change the field to Pass/Fail...but my peeps like shiny colors to go along with it...</p>
  
  <pre><code>XSSFWorkbook wb = new XSSFWorkbook();
  XSSFSheet sh = (XSSFSheet)wb.CreateSheet("ACT");
  
  string cf = "IF(" + engCell + (detailRow.RowNum + 1) + @"&gt;17,""Pass :)"", ""Fail :("")";
  detailRow.CreateCell(detailIdx);
  detailRow.GetCell(detailIdx).SetCellType(CellType.Formula);
  detailRow.GetCell(detailIdx++).SetCellFormula(cf);
  </code></pre>