NPOI set custom cell background color [RGB format]

    Public Sub SetCellBackColorCustomColorRGB()

        Dim srcWB As HSSFWorkbook = Nothing

        Dim filePath = "C:\test.xls"

        Using fs As New FileStream(filePath, FileMode.Open, FileAccess.Read)

            srcWB = New HSSFWorkbook(fs)

        End Using

        Dim sheet As HSSFSheet = srcWB.GetSheetAt(0)

        Dim cell As HSSFCell = sheet.GetRow(1).GetCell(1)

        Dim style As HSSFCellStyle = srcWB.CreateCellStyle

        'Get custom palette

        Dim palette = srcWB.GetCustomPalette

        'Set color index at palette

        palette.SetColorAtIndex(57, 184, 255, 113)

        'Set color from color palette

        style.FillForegroundColor = palette.GetColor(57).GetIndex

        style.FillPattern = FillPattern.SolidForeground

        cell.CellStyle = style

        Dim savePath As String = filePath

        Using fs As New FileStream(savePath, FileMode.Create, FileAccess.Write)

            srcWB.Write(fs)

        End Using

        MsgBox("done")

    End Sub