Excel VSTO C# change Marker fill color of Chart series always apply only 1 color to multiple series

Question

I am trying to change Marker Fore Color of series 4 and 6 to two different colors, but somehow they have the same color. Please kindly advice

series1.Format.Line.ForeColor.RGB = (int)(0x000000);
        series2.Format.Line.ForeColor.RGB = (int)(0xFF0000);
        series3.Format.Line.ForeColor.RGB = (int)(0xA9D18E);

        series4.Select();
        series4.Format.Line.Visible = Microsoft.Office.Core.MsoTriState.msoFalse;
        series4.MarkerStyle = XlMarkerStyle.xlMarkerStyleAutomatic;
        series4.Format.Fill.ForeColor.RGB = (int)(0x0000FF);
        series4.Format.Fill.Visible = Microsoft.Office.Core.MsoTriState.msoTrue;
        series4.Format.Fill.Solid();
       

        series5.Select();
        series5.Format.Line.ForeColor.RGB = (int)(0x9609ED);

        series6.Select();
        series6.Format.Line.Visible = Microsoft.Office.Core.MsoTriState.msoFalse;
        series6.MarkerStyle = XlMarkerStyle.xlMarkerStyleAutomatic;
       
        series6.Format.Fill.ForeColor.RGB = (int)(0xED7D31);
        series6.Format.Fill.Visible = Microsoft.Office.Core.MsoTriState.msoTrue;
        series6.Format.Fill.Solid();

I also generate VBA macro from Excel (for comparing), the macro will only turns 2 series from Lines to no-line and change Marker color only. This macro works.

Sub Macro1()

ActiveSheet.ChartObjects("Chart 1").Activate
ActiveChart.FullSeriesCollection(5).Select
Selection.Format.Line.Visible = msoFalse
Selection.MarkerStyle = -4105
With Selection.Format.Fill
    .Visible = msoTrue
    .ForeColor.ObjectThemeColor = msoThemeColorAccent2
    .ForeColor.TintAndShade = 0
    .ForeColor.Brightness = -0.25
    .Transparency = 0
    .Solid
End With
ActiveChart.FullSeriesCollection(2).Select
Selection.Format.Line.Visible = msoFalse
Selection.MarkerStyle = -4105
Selection.Format.Line.Visible = msoFalse
Selection.Format.Line.Visible = msoFalse
With Selection.Format.Fill
    .Visible = msoTrue
    .ForeColor.ObjectThemeColor = msoThemeColorAccent5
    .ForeColor.TintAndShade = 0
    .ForeColor.Brightness = -0.25
    .Transparency = 0
    .Solid
End With
End Sub

Updated Solution: I found solution, even not sure why it is: just change order of the statement as below

series6.Select();
series6.Format.Line.Visible = 
Microsoft.Office.Core.MsoTriState.msoFalse;
series6.MarkerStyle = XlMarkerStyle.xlMarkerStyleAutomatic;
series6.Format.Fill.Visible = 
Microsoft.Office.Core.MsoTriState.msoTrue;
series6.Format.Fill.Solid();
series6.Format.Fill.ForeColor.RGB = (int)(0xED7D31);