public static void ApplyFormattingToField(ViewSchedule schedule, int fieldIndex)
{
    // Get the field.
    ScheduleDefinition definition = schedule.Definition;
    ScheduleField field = definition.GetField(fieldIndex);

    // Build unit formatting for the field.
    FormatOptions options = field.GetFormatOptions();
    options.UseDefault = false;
    options.SetUnitTypeId(UnitTypeId.SquareInches);
    options.SetSymbolTypeId(SymbolTypeId.InSup2);

    // Build style overrides for the field
    // Use override options to indicate fields that are overridden and apply changes
    TableCellStyle style = field.GetStyle();
    TableCellStyleOverrideOptions overrideOptions = style.GetCellStyleOverrideOptions();
    overrideOptions.BackgroundColor = true;
    style.BackgroundColor = new Color(0x00, 0x00, 0xFF);
    overrideOptions.FontColor = true;
    style.TextColor = new Color(0xFF, 0xFF, 0xFF);
    overrideOptions.Italics = true;
    style.IsFontItalic = true;

    style.SetCellStyleOverrideOptions(overrideOptions);

    double width = field.GridColumnWidth;

    using (Transaction t = new Transaction(schedule.Document, "Set style etc"))
    {
        t.Start();
        field.SetStyle(style);
        field.SetFormatOptions(options);
        // Change column width (affects width in grid and on sheet) - units are in Revit length units - ft.
        field.GridColumnWidth = width + 0.5;
        t.Commit();
    }
}

Public Shared Sub ApplyFormattingToField(schedule As ViewSchedule, fieldIndex As Integer)
    ' Get the field.
    Dim definition As ScheduleDefinition = schedule.Definition
    Dim field As ScheduleField = definition.GetField(fieldIndex)

    ' Build unit formatting for the field.
    Dim options As FormatOptions = field.GetFormatOptions()
    options.UseDefault = False
    options.SetUnitTypeId(UnitTypeId.SquareInches)
    options.SetSymbolTypeId(SymbolTypeId.InSup2)

    ' Build style overrides for the field
    ' Use override options to indicate fields that are overridden and apply changes
    Dim style As TableCellStyle = field.GetStyle()
    Dim overrideOptions As TableCellStyleOverrideOptions = style.GetCellStyleOverrideOptions()
    overrideOptions.BackgroundColor = True
    style.BackgroundColor = New Color(&H0, &H0, &HFF)
    overrideOptions.FontColor = True
    style.TextColor = New Color(&HFF, &HFF, &HFF)
    overrideOptions.Italics = True
    style.IsFontItalic = True

    style.SetCellStyleOverrideOptions(overrideOptions)

    Dim width As Double = field.GridColumnWidth

    Using t As New Transaction(schedule.Document, "Set style etc")
        t.Start()
        field.SetStyle(style)
        field.SetFormatOptions(options)
        ' Change column width (affects width in grid and on sheet) - units are in Revit length units - ft.
        field.GridColumnWidth = width + 0.5
        t.Commit()
    End Using
End Sub