title: JExcel API : how to change the color of a Cell?
body: <p>I search how to change the color of a cell, selected in a Excel file.
  I tested this code : </p>
  
  <pre><code>    WritableCell c = sheet.getWritableCell(0,0);
      WritableCellFormat newFormat = new WritableCellFormat(c.getCellFormat());
      newFormat.setBackground(Colour.RED);
      c.setCellFormat(newFormat);
  </code></pre>
  
  <p>But this example doesn't run.
  What is the solution ?</p>