cell.Style.ForegroundColor = Color.Empty;

When applying Color.Empty to a cell that previously contained a color, the cell still gets filled with Color.White

Then which color do you want to fill it into a cell?

None. Similar to the ‘No Fill’ action in Excel.

Please try :

cell.Style.ForegroundColor = Color.Empty;

cell.Style.BackgroundColor = Color.Empty;

cell.Style.Style.Pattern = BackgroundType.None;

Clearing the pattern did the trick! Thanks for the help.