Coloring bar graph type

[Valgo54]

Hello
I am encountering problem in coloring a bar graph chart in a PPT presentation.
I am doing that with excel vba macro 2007. The same code is working with grao bubble and istogram.
Any help will be appreciated.
Thanks

Private pptApp As PowerPoint.Application
Private xlapp As Excel.Application
Private strPowerpointModelPath As String, oPowerpointModel As Object
Private strPowerpointPresentation As String
Private Opptfile As PowerPoint.Presentation
Private oChartShape As Object
Private ChartSource As Range
Private wschart As Worksheet
Dim col, num_tot_col, ws_input_rows, num_slide, i, l As Integer

 Sub Mod_graf()
    
    Set xlapp = GetObject(, "Excel.Application")
    If Err.Number <> 0 Then
        Err.Clear
        Set xlapp = CreateObject("Excel.Application")
    End If
    
    
    ' apro il file ppt
    Set pptApp = CreateObject("Powerpoint.Application")
    pptApp.Visible = True
    With ThisWorkbook
        strPowerpointPresentation = ThisWorkbook.Path & "\" & "mod_graf_barre_1" & ".pptx"
    End With
    
    Set Opptfile = pptApp.Presentations.Open(Filename:=strPowerpointPresentation, WithWindow:=msoTrue, Untitled:=msoTrue)
    num_slide = 1
       
    ApreChart Opptfile.Slides(num_slide).Shapes("Chart")
        
    ModChart
        
    ChiudeChart
 
    Opptfile.SaveAs (strPowerpointPresentation)
    Opptfile.Close
    Set Opptfile = Nothing
    pptApp.Quit
    MsgBox "Grafici bubble elaborati.", vbInformation
    

End Sub
Sub ModChart()

        oChartShape.Chart.SeriesCollection(1).Points(1).Interior.Color = RGB(0, 255, 0) 'green
        oChartShape.Chart.SeriesCollection(2).Points(1).Interior.Color = RGB(143, 0, 255) 'violet
        oChartShape.Chart.SeriesCollection(3).Points(1).Interior.Color = RGB(255, 255, 51) ' yellow
    
End Sub

Sub ChiudeChart(Optional bParam As Boolean)
    oChartShape.Chart.Refresh
    Set wschart = Nothing
    oChartShape.Chart.ChartData.Workbook.Close
    Set oChartShape = Nothing
End Sub

Sub ApreChart(oChart)
   Set oChartShape = oChart
    oChartShape.Chart.ChartData.Activate

End Sub

 

[Valgo54]

Hello
I solved with
oChartShape.Chart.SeriesCollection(1).Points(1).Format.Fill.ForeColor.RGB = RGB(0, 0, 255) ' blu color