Color datagrid export to excel

I have some code that exports a datagrid to an excel file that works very well except it will not export the datagrid's formatted cells.

First, I use an OpenFileDialog to import an excel file into a datagrid...
Then I format some of the cells based on certain variables:


    Private Sub customerDataGridView_CellFormatting(ByVal sender As Object, ByVal e As DataGridViewCellFormattingEventArgs) Handles customerDataGridView.CellFormatting


        If Me.customerDataGridView.Columns(e.ColumnIndex).Name = "COLUMN TITLE" Then

            If e.Value IsNot Nothing Then

                If CDbl(e.Value.ToString) > CDbl(My.Settings.FDr2LowValue) And CDbl(e.Value.ToString) < CDbl(My.Settings.FDr2HighValue) Then

                    e.CellStyle.BackColor = My.Settings.FDRcolor

                End If

            End If

        End If

End Sub

then here is the code I use to export to excel, but the formatting does not stick during the export...


        Dim rowsTotal, colsTotal As Short

        Dim I, j, iC As Short

        System.Windows.Forms.Cursor.Current = System.Windows.Forms.Cursors.WaitCursor

        Dim xlApp As New Excel.Application


        Try

            Dim excelBook As Excel.Workbook = xlApp.Workbooks.Add

            Dim excelWorksheet As Excel.Worksheet = CType(excelBook.Worksheets(1), Excel.Worksheet)

            xlApp.Visible = True

            rowsTotal = CShort(customerDataGridView.RowCount - 1)

            colsTotal = CShort(customerDataGridView.Columns.Count - 1)


            With excelWorksheet

                .Cells.Select()

                .Cells.Delete()

                For iC = 0 To colsTotal

                    .Cells(1, iC + 1).Value = customerDataGridView.Columns(iC).HeaderText

                Next


                For I = 0 To rowsTotal

                    For j = 0 To colsTotal

                        .Cells(I + 2, j + 1).value = customerDataGridView.Rows(I).Cells(j).Value

                    Next j

                Next I


                .Rows("1:1").Font.FontStyle = "Bold"

                .Rows("1:1").Font.Size = 10

                .Cells.Columns.AutoFit()

                .Cells.Select()

                .Cells.EntireColumn.AutoFit()

                .Cells(1, 1).Select()

            End With




        Catch ex As Exception

            MsgBox("ex.tostring")

        Finally

            'RELEASE ALLOACTED RESOURCES

            System.Windows.Forms.Cursor.Current = System.Windows.Forms.Cursors.Default

            xlApp = Nothing

        End Try