Created Unassigned: Style.Font.FontColor incorrectly determined [9340]

Hi,

In attachment a small excel file: the font color for cells C6, C7, C8, C9 is __black__ (as can be verified by vba).

However ClosedXML returns the color __Silver__ for these cells.

Code snippet:
var wbSource = new XLWorkbook(@"d:\ColorBook.xlsx");
var ws = wbSource.Worksheet("Sheet1");
for (int row = 1; row < 10; row++)
{
Console.WriteLine("The result for cell C" + row + " is " + ws.Cell("C" + row).Style.Font.FontColor.Color.ToString());
}

I can't seem to find to code that causes the problem. Any suggestion for a work around is also appreciated.