FarPoint.Win.Spread.Model.DefaultSheetStyleModel defstyleModel = new FarPoint.Win.Spread.Model.DefaultSheetStyleModel();
FarPoint.Win.Spread.StyleInfo sInfo = new FarPoint.Win.Spread.StyleInfo();
defstyleModel = (FarPoint.Win.Spread.Model.DefaultSheetStyleModel)fpSpread1.ActiveSheet.Models.Style;
sInfo.BackColor = Color.LightBlue;
defstyleModel.SetDirectInfo(0, 0, sInfo);
string fileName;
fileName = "D:\\Temp\\myser.xml";
System.IO.Stream stream;
stream = System.IO.File.Open(fileName, System.IO.FileMode.Create);
System.Xml.XmlTextWriter writer = new System.Xml.XmlTextWriter(stream, System.Text.Encoding.UTF8);
writer.Formatting = System.Xml.Formatting.Indented;
writer.Indentation = 2;
writer.WriteStartDocument();
writer.WriteStartElement("Style");
defstyleModel.Serialize(writer);
writer.WriteEndElement();
writer.WriteEndDocument();
writer.Close();